CVE-2020-28016: Heap out-of-bounds write in parse_fix_phrase()

[exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index a761036889096ea323eddca098a8ef283cb7151e..68d9c056f6623fb9c51c1987f1ae7f4262cf0c53 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -51,6 +51,8 @@
 .set ACL "access control lists (ACLs)"
 .set I   "    "
 
 .set ACL "access control lists (ACLs)"
 .set I   "    "
 

+.set drivernamemax "64"
+

 .macro copyyear
 2020
 .endmacro
 .macro copyyear
 2020
 .endmacro


@@ -3848,9 +3850,11 @@ headers.)
 .cindex "Solaris" "&'mail'& command"
 .cindex "dot" "in incoming non-SMTP message"
 This option, which has the same effect as &%-oi%&, specifies that a dot on a
 .cindex "Solaris" "&'mail'& command"
 .cindex "dot" "in incoming non-SMTP message"
 This option, which has the same effect as &%-oi%&, specifies that a dot on a

-line by itself should not terminate an incoming, non-SMTP message. I can find
-no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
-command in Solaris 2.4 uses it. See also &%-ti%&.
+line by itself should not terminate an incoming, non-SMTP message.
+Solaris 2.4 (SunOS 5.4) Sendmail has a similar &%-i%& processing option
+&url(https://docs.oracle.com/cd/E19457-01/801-6680-1M/801-6680-1M.pdf),
+p. 1M-529), and therefore a &%-oi%& command line option, which both are used
+by its &'mailx'& command.

 
 .vitem &%-L%&&~<&'tag'&>
 .oindex "&%-L%&"
 
 .vitem &%-L%&&~<&'tag'&>
 .oindex "&%-L%&"


@@ -3940,12 +3944,31 @@ This option is not intended for use by external callers. It is used internally
 by Exim in conjunction with the &%-MC%& option. It signifies that a
 remote host supports the ESMTP &_CHUNKING_& extension.
 
 by Exim in conjunction with the &%-MC%& option. It signifies that a
 remote host supports the ESMTP &_CHUNKING_& extension.
 

+.new
+.vitem &%-MCL%&
+.oindex "&%-MCL%&"
+This option is not intended for use by external callers. It is used internally
+by Exim in conjunction with the &%-MC%& option. It signifies that the server to
+which Exim is connected advertised limits on numbers of mails, recipients or
+recipient domains.
+The limits are given by the following three arguments.
+.wen
+

 .vitem &%-MCP%&
 .oindex "&%-MCP%&"
 This option is not intended for use by external callers. It is used internally
 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
 which Exim is connected supports pipelining.
 
 .vitem &%-MCP%&
 .oindex "&%-MCP%&"
 This option is not intended for use by external callers. It is used internally
 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
 which Exim is connected supports pipelining.
 

+.new
+.vitem &%-MCp%&
+.oindex "&%-MCp%&"
+This option is not intended for use by external callers. It is used internally
+by Exim in conjunction with the &%-MC%& option. It signifies that the connection
+t a remote server is via a SOCKS proxy, using addresses and ports given by
+the following four arguments.
+.wen
+

 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
 .oindex "&%-MCQ%&"
 This option is not intended for use by external callers. It is used internally
 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
 .oindex "&%-MCQ%&"
 This option is not intended for use by external callers. It is used internally


@@ -4151,8 +4174,9 @@ the standard output. This option can be used only by an admin user.
 
 .vitem &%-m%&
 .oindex "&%-m%&"
 
 .vitem &%-m%&
 .oindex "&%-m%&"

-This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
-treats it that way too.
+This is a synonym for &%-om%& that is accepted by Sendmail
+(&url(https://docs.oracle.com/cd/E19457-01/801-6680-1M/801-6680-1M.pdf)
+p. 1M-258), so Exim treats it that way too.

 
 .vitem &%-N%&
 .oindex "&%-N%&"
 
 .vitem &%-N%&
 .oindex "&%-N%&"


@@ -5949,7 +5973,7 @@ Libraries you use may depend on specific environment settings.  This
 imposes a security risk (e.g. PATH). There are two lists:
 &%keep_environment%& for the variables to import as they are, and
 &%add_environment%& for variables we want to set to a fixed value.
 imposes a security risk (e.g. PATH). There are two lists:
 &%keep_environment%& for the variables to import as they are, and
 &%add_environment%& for variables we want to set to a fixed value.

-Note that TZ is handled separately, by the $%timezone%$ runtime
+Note that TZ is handled separately, by the &%timezone%& runtime

 option and by the TIMEZONE_DEFAULT buildtime option.
 .code
 # keep_environment = ^LDAP
 option and by the TIMEZONE_DEFAULT buildtime option.
 .code
 # keep_environment = ^LDAP


@@ -8483,7 +8507,7 @@ will store a result in the &$local_part_data$& variable.
 .vitem domains
 .new
 A &%domains%& router option or &%domains%& ACL condition
 .vitem domains
 .new
 A &%domains%& router option or &%domains%& ACL condition

-will store a result in the &$domain_data$& variable
+will store a result in the &$domain_data$& variable.

 .wen
 .vitem senders
 A &%senders%& router option or &%senders%& ACL condition
 .wen
 .vitem senders
 A &%senders%& router option or &%senders%& ACL condition


@@ -8836,7 +8860,7 @@ If the pattern starts with the name of a lookup type
 of either kind (single-key or query-style) it may be
 followed by a comma and options,
 The options are lookup-type specific and consist of a comma-separated list.
 of either kind (single-key or query-style) it may be
 followed by a comma and options,
 The options are lookup-type specific and consist of a comma-separated list.

-Each item starts with a tag and and equals "=".
+Each item starts with a tag and and equals "=" sign.

 
 .next
 .cindex "domain list" "matching literal domain name"
 
 .next
 .cindex "domain list" "matching literal domain name"


@@ -8955,9 +8979,13 @@ accept hosts = @[]
 .endd
 .next
 .cindex "CIDR notation"
 .endd
 .next
 .cindex "CIDR notation"

-If the pattern is an IP address followed by a slash and a mask length (for
-example 10.11.42.0/24), it is matched against the IP address of the subject
-host under the given mask. This allows, an entire network of hosts to be
+If the pattern is an IP address followed by a slash and a mask length, for
+example
+.code
+10.11.42.0/24
+.endd
+, it is matched against the IP address of the subject
+host under the given mask. This allows an entire network of hosts to be

 included (or excluded) by a single item. The mask uses CIDR notation; it
 specifies the number of address bits that must match, starting from the most
 significant end of the address.
 included (or excluded) by a single item. The mask uses CIDR notation; it
 specifies the number of address bits that must match, starting from the most
 significant end of the address.


@@ -10146,7 +10174,7 @@ They are visible in DKIM, PRDR and DATA ACLs.
 Header lines that are added in a RCPT ACL (for example)
 are saved until the message's incoming header lines are available, at which
 point they are added.
 Header lines that are added in a RCPT ACL (for example)
 are saved until the message's incoming header lines are available, at which
 point they are added.

-When any of the above ACLs ar
+When any of the above ACLs are

 running, however, header lines added by earlier ACLs are visible.
 
 Upper case and lower case letters are synonymous in header names. If the
 running, however, header lines added by earlier ACLs are visible.
 
 Upper case and lower case letters are synonymous in header names. If the


@@ -10422,10 +10450,11 @@ additional arguments need be given; the maximum number permitted, including the
 name of the subroutine, is nine.
 
 The return value of the subroutine is inserted into the expanded string, unless
 name of the subroutine, is nine.
 
 The return value of the subroutine is inserted into the expanded string, unless

-the return value is &%undef%&. In that case, the expansion fails in the same
-way as an explicit &"fail"& on a lookup item. The return value is a scalar.
-Whatever you return is evaluated in a scalar context. For example, if you
-return the name of a Perl vector, the return value is the size of the vector,
+the return value is &%undef%&. In that case, the entire expansion is
+forced to fail, in the same way as an explicit &"fail"& on a lookup item
+does (see section &<<SECTforexpfai>>&).  Whatever you return is evaluated
+in a scalar context, thus the return value is a scalar.  For example, if you
+return a Perl vector, the return value is the size of the vector,

 not its contents.
 
 If the subroutine exits by calling Perl's &%die%& function, the expansion fails
 not its contents.
 
 If the subroutine exits by calling Perl's &%die%& function, the expansion fails


@@ -10475,7 +10504,7 @@ For more discussion and an example, see section &<<SECTverifyPRVS>>&.
 .cindex "expansion" "inserting an entire file"
 .cindex "file" "inserting into expansion"
 .cindex "&%readfile%& expansion item"
 .cindex "expansion" "inserting an entire file"
 .cindex "file" "inserting into expansion"
 .cindex "&%readfile%& expansion item"

-The filename and end-of-line string are first expanded separately. The file is
+The filename and end-of-line (eol) string are first expanded separately. The file is

 then read, and its contents replace the entire item. All newline characters in
 the file are replaced by the end-of-line string if it is present. Otherwise,
 newlines are left in the string.
 then read, and its contents replace the entire item. All newline characters in
 the file are replaced by the end-of-line string if it is present. Otherwise,
 newlines are left in the string.


@@ -10512,7 +10541,7 @@ ${readsocket{inet:[::1]:1234}{request string}}
 Only a single host name may be given, but if looking it up yields more than
 one IP address, they are each tried in turn until a connection is made. For
 both kinds of socket, Exim makes a connection, writes the request string
 Only a single host name may be given, but if looking it up yields more than
 one IP address, they are each tried in turn until a connection is made. For
 both kinds of socket, Exim makes a connection, writes the request string

-unless it is an empty string; and no terminating NUL is ever sent)
+(unless it is an empty string; no terminating NUL is ever sent)

 and reads from the socket until an end-of-file
 is read. A timeout of 5 seconds is applied. Additional, optional arguments
 extend what can be done. Firstly, you can vary the timeout. For example:
 and reads from the socket until an end-of-file
 is read. A timeout of 5 seconds is applied. Additional, optional arguments
 extend what can be done. Firstly, you can vary the timeout. For example:


@@ -10978,7 +11007,7 @@ is controlled by the &%print_topbitchars%& option.
 .vitem &*${escape8bit:*&<&'string'&>&*}*&
 .cindex "expansion" "escaping 8-bit characters"
 .cindex "&%escape8bit%& expansion item"
 .vitem &*${escape8bit:*&<&'string'&>&*}*&
 .cindex "expansion" "escaping 8-bit characters"
 .cindex "&%escape8bit%& expansion item"

-If the string contains and characters with the most significant bit set,
+If the string contains any characters with the most significant bit set,

 they are converted to escape sequences starting with a backslash.
 Backslashes and DEL characters are also converted.
 
 they are converted to escape sequences starting with a backslash.
 Backslashes and DEL characters are also converted.
 


@@ -11174,6 +11203,10 @@ If the optional type is given it must be one of "a", "d", "h" or "l"
 and selects address-, domain-, host- or localpart- lists to search among respectively.
 Otherwise all types are searched in an undefined order and the first
 matching list is returned.
 and selects address-, domain-, host- or localpart- lists to search among respectively.
 Otherwise all types are searched in an undefined order and the first
 matching list is returned.

+.new
+&*Note*&: Neither string-expansion of lists referenced by named-list syntax elements,
+nor expansion of lookup elements, is done by the &%listnamed%& operator.
+.wen

 
 
 .vitem &*${local_part:*&<&'string'&>&*}*&
 
 
 .vitem &*${local_part:*&<&'string'&>&*}*&


@@ -11441,7 +11474,7 @@ Now deprecated, a synonym for the &%base64%& expansion operator.
 .cindex "expansion" "string length"
 .cindex "string" "length in expansion"
 .cindex "&%strlen%& expansion item"
 .cindex "expansion" "string length"
 .cindex "string" "length in expansion"
 .cindex "&%strlen%& expansion item"

-The item is replace by the length of the expanded string, expressed as a
+The item is replaced by the length of the expanded string, expressed as a

 decimal number. &*Note*&: Do not confuse &%strlen%& with &%length%&.
 All measurement is done in bytes and is not UTF-8 aware.
 
 decimal number. &*Note*&: Do not confuse &%strlen%& with &%length%&.
 All measurement is done in bytes and is not UTF-8 aware.
 


@@ -17361,7 +17394,7 @@ or if the message was submitted locally (not using TCP/IP), and the &%-bnq%&
 option was not set.
 
 
 option was not set.
 
 

-.option recipients_max main integer 0
+.option recipients_max main integer 50000

 .cindex "limit" "number of recipients"
 .cindex "recipient" "maximum number"
 If this option is set greater than zero, it specifies the maximum number of
 .cindex "limit" "number of recipients"
 .cindex "recipient" "maximum number"
 If this option is set greater than zero, it specifies the maximum number of


@@ -18318,8 +18351,12 @@ if the OpenSSL build supports TLS extensions and the TLS client sends the
 Server Name Indication extension, then this option and others documented in
 &<<SECTtlssni>>& will be re-expanded.
 
 Server Name Indication extension, then this option and others documented in
 &<<SECTtlssni>>& will be re-expanded.
 

-If this option is unset or empty a fresh self-signed certificate will be
-generated for every connection.
+If this option is unset or empty a self-signed certificate will be
+.new
+used.
+Under Linux this is generated at daemon startup; on other platforms it will be
+generated fresh for every connection.
+.wen

 
 .option tls_crl main string&!! unset
 .cindex "TLS" "server certificate revocation list"
 
 .option tls_crl main string&!! unset
 .cindex "TLS" "server certificate revocation list"


@@ -18767,6 +18804,11 @@ which the preconditions are tested. The order of expansion of the options that
 provide data for a transport is: &%errors_to%&, &%headers_add%&,
 &%headers_remove%&, &%transport%&.
 
 provide data for a transport is: &%errors_to%&, &%headers_add%&,
 &%headers_remove%&, &%transport%&.
 

+.new
+The name of a router is limited to be &drivernamemax; ASCII characters long;
+prior to Exim 4.95 names would be silently truncated at this length, but now
+it is enforced.
+.wen

 
 
 .option address_data routers string&!! unset
 
 
 .option address_data routers string&!! unset


@@ -22310,6 +22352,12 @@ and &$original_domain$& is never set.
 .scindex IIDgenoptra1 "generic options" "transport"
 .scindex IIDgenoptra2 "options" "generic; for transports"
 .scindex IIDgenoptra3 "transport" "generic options for"
 .scindex IIDgenoptra1 "generic options" "transport"
 .scindex IIDgenoptra2 "options" "generic; for transports"
 .scindex IIDgenoptra3 "transport" "generic options for"

+.new
+The name of a transport is limited to be &drivernamemax; ASCII characters long;
+prior to Exim 4.95 names would be silently truncated at this length, but now
+it is enforced.
+.wen
+

 The following generic options apply to all transports:
 
 
 The following generic options apply to all transports:
 
 


@@ -22985,6 +23033,11 @@ If &%file%& or &%directory%& is set for a delivery from a redirection, it is
 used to determine the file or directory name for the delivery. Normally, the
 contents of &$address_file$& are used in some way in the string expansion.
 .endlist
 used to determine the file or directory name for the delivery. Normally, the
 contents of &$address_file$& are used in some way in the string expansion.
 .endlist

+If the &%create_file%& option is set to a path which
+matches (see the option definition below for details)
+a file or directory name
+for the delivery, that name becomes de-tainted.
+

 .cindex "tainted data" "in filenames"
 .cindex appendfile "tainted data"
 Tainted data may not be used for a file or directory name.
 .cindex "tainted data" "in filenames"
 .cindex appendfile "tainted data"
 Tainted data may not be used for a file or directory name.


@@ -23132,14 +23185,34 @@ directories defined by the &%directory%& option. In the case of maildir
 delivery, it applies to the top level directory, not the maildir directories
 beneath.
 
 delivery, it applies to the top level directory, not the maildir directories
 beneath.
 

+.new

 The option must be set to one of the words &"anywhere"&, &"inhome"&, or
 The option must be set to one of the words &"anywhere"&, &"inhome"&, or

-&"belowhome"&. In the second and third cases, a home directory must have been
-set for the transport. This option is not useful when an explicit filename is
+&"belowhome"&, or to an absolute path.
+.wen
+
+In the second and third cases, a home directory must have been
+set for the transport, and the file or directory being created must
+reside within it.
+The "belowhome" checking additionally checks for attempts to use "../"
+to evade the testing.
+This option is not useful when an explicit filename is

 given for normal mailbox deliveries. It is intended for the case when filenames
 are generated from users' &_.forward_& files. These are usually handled
 by an &(appendfile)& transport called &%address_file%&. See also
 &%file_must_exist%&.
 
 given for normal mailbox deliveries. It is intended for the case when filenames
 are generated from users' &_.forward_& files. These are usually handled
 by an &(appendfile)& transport called &%address_file%&. See also
 &%file_must_exist%&.
 

+.new
+In the fourth case,
+the value given for this option must be an absolute path for an
+existing directory.
+The value is used for checking instead of a home directory;
+checking is done in "belowhome" mode.
+
+.cindex "tainted data" "de-tainting"
+If "belowhome" checking is used, the file or directory path
+becomes de-tainted.
+.wen
+

 
 .option directory appendfile string&!! unset
 This option is mutually exclusive with the &%file%& option, but one of &%file%&
 
 .option directory appendfile string&!! unset
 This option is mutually exclusive with the &%file%& option, but one of &%file%&


@@ -23152,6 +23225,11 @@ appended to a single mailbox file. A number of different formats are provided
 (see &%maildir_format%& and &%mailstore_format%&), and see section
 &<<SECTopdir>>& for further details of this form of delivery.
 
 (see &%maildir_format%& and &%mailstore_format%&), and see section
 &<<SECTopdir>>& for further details of this form of delivery.
 

+.new
+The result of expansion must not be tainted, unless the &%create_file%& option
+specifies a path.
+.wen
+

 
 .option directory_file appendfile string&!! "see below"
 .cindex "base62"
 
 .option directory_file appendfile string&!! "see below"
 .cindex "base62"


@@ -23184,6 +23262,11 @@ specifies a single file, to which the message is appended. One or more of
 &%use_fcntl_lock%&, &%use_flock_lock%&, or &%use_lockfile%& must be set with
 &%file%&.
 
 &%use_fcntl_lock%&, &%use_flock_lock%&, or &%use_lockfile%& must be set with
 &%file%&.
 

+.new
+The result of expansion must not be tainted, unless the &%create_file%& option
+specifies a path.
+.wen
+

 .cindex "NFS" "lock file"
 .cindex "locking files"
 .cindex "lock files"
 .cindex "NFS" "lock file"
 .cindex "locking files"
 .cindex "lock files"


@@ -25677,7 +25760,7 @@ has advertised support for IGNOREQUOTA in its response to the LHLO command.
 This option limits the number of RCPT commands that are sent in a single
 SMTP message transaction. Each set of addresses is treated independently, and
 so can cause parallel connections to the same host if &%remote_max_parallel%&
 This option limits the number of RCPT commands that are sent in a single
 SMTP message transaction. Each set of addresses is treated independently, and
 so can cause parallel connections to the same host if &%remote_max_parallel%&

-permits this.
+permits this. A value setting of zero disables the limit.

 
 
 .new
 
 
 .new


@@ -27111,6 +27194,12 @@ permitted to use it as a relay. SMTP authentication is not of relevance to the
 transfer of mail between servers that have no managerial connection with each
 other.
 
 transfer of mail between servers that have no managerial connection with each
 other.
 

+.new
+The name of an authenticator is limited to be &drivernamemax; ASCII characters long;
+prior to Exim 4.95 names would be silently truncated at this length, but now
+it is enforced.
+.wen
+

 .cindex "AUTH" "description of"
 .cindex "ESMTP extensions" AUTH
 Very briefly, the way SMTP authentication works is as follows:
 .cindex "AUTH" "description of"
 .cindex "ESMTP extensions" AUTH
 Very briefly, the way SMTP authentication works is as follows:


@@ -38079,7 +38168,7 @@ implying the use of a default path.
 When Exim encounters an empty item in the list, it searches the list defined by
 LOG_FILE_PATH, and uses the first item it finds that is neither empty nor
 &"syslog"&. This means that an empty item in &%log_file_path%& can be used to
 When Exim encounters an empty item in the list, it searches the list defined by
 LOG_FILE_PATH, and uses the first item it finds that is neither empty nor
 &"syslog"&. This means that an empty item in &%log_file_path%& can be used to

-mean &"use the path specified at build time"&. It no such item exists, log
+mean &"use the path specified at build time"&. If no such item exists, log

 files are written in the &_log_& subdirectory of the spool directory. This is
 equivalent to the setting:
 .code
 files are written in the &_log_& subdirectory of the spool directory. This is
 equivalent to the setting:
 .code


@@ -38624,6 +38713,7 @@ selection marked by asterisks:
 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs
 &` queue_time                 `&  time on queue for one recipient
 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs
 &` queue_time                 `&  time on queue for one recipient

+&`*queue_time_exclusive       `&  exclude recieve time from QT times

 &` queue_time_overall         `&  time on queue for whole message
 &` pid                        `&  Exim process id
 &` pipelining                 `&  PIPELINING use, on <= and => lines
 &` queue_time_overall         `&  time on queue for whole message
 &` pid                        `&  Exim process id
 &` pipelining                 `&  PIPELINING use, on <= and => lines


@@ -38865,18 +38955,13 @@ Delivery "L" fields have an asterisk appended if used.
 .cindex "log" "queue time"
 &%queue_time%&: The amount of time the message has been in the queue on the
 local host is logged as QT=<&'time'&> on delivery (&`=>`&) lines, for example,
 .cindex "log" "queue time"
 &%queue_time%&: The amount of time the message has been in the queue on the
 local host is logged as QT=<&'time'&> on delivery (&`=>`&) lines, for example,

-&`QT=3m45s`&. The clock starts when Exim starts to receive the message, so it
-includes reception time as well as the delivery time for the current address.
-This means that it may be longer than the difference between the arrival and
-delivery log line times, because the arrival log line is not written until the
-message has been successfully received.
+&`QT=3m45s`&.

 If millisecond logging is enabled, short times will be shown with greater
 precision, eg. &`QT=1.578s`&.
 .next
 &%queue_time_overall%&: The amount of time the message has been in the queue on
 the local host is logged as QT=<&'time'&> on &"Completed"& lines, for
 If millisecond logging is enabled, short times will be shown with greater
 precision, eg. &`QT=1.578s`&.
 .next
 &%queue_time_overall%&: The amount of time the message has been in the queue on
 the local host is logged as QT=<&'time'&> on &"Completed"& lines, for

-example, &`QT=3m45s`&. The clock starts when Exim starts to receive the
-message, so it includes reception time as well as the total delivery time.
+example, &`QT=3m45s`&.

 .next
 .cindex "log" "receive duration"
 &%receive_time%&: For each message, the amount of real time it has taken to
 .next
 .cindex "log" "receive duration"
 &%receive_time%&: For each message, the amount of real time it has taken to


@@ -38935,10 +39020,12 @@ it is too big.
 .cindex "log" "frozen messages; skipped"
 .cindex "frozen messages" "logging skipping"
 &%skip_delivery%&: A log line is written whenever a message is skipped during a
 .cindex "log" "frozen messages; skipped"
 .cindex "frozen messages" "logging skipping"
 &%skip_delivery%&: A log line is written whenever a message is skipped during a

-queue run because it is frozen or because another process is already delivering
-it.
+queue run because it another process is already delivering it or because
+it is frozen.

 .cindex "&""spool file is locked""&"
 .cindex "&""spool file is locked""&"

-The message that is written is &"spool file is locked"&.
+.cindex "&""message is frozen""&"
+The message that is written is either &"spool file is locked"& or
+&"message is frozen"&.

 .next
 .cindex "log" "smtp confirmation"
 .cindex "SMTP" "logging confirmation"
 .next
 .cindex "log" "smtp confirmation"
 .cindex "SMTP" "logging confirmation"