From: Phil Pennock <phil+git@pennock-tech.com>
Date: Thu, 29 Oct 2020 23:00:51 +0000 (-0400)
Subject: SECURITY: fix Qualys CVE-2020-PFPSN
X-Git-Tag: exim-4.95-RC0~51^2~46
X-Git-Url: https://git.exim.org/exim.git/commitdiff_plain/cb08e2f59f2166660abc998a0554e64c61d4a0f5?ds=inline;hp=5dc522966ae58ac845dc280495af651c9858f152

SECURITY: fix Qualys CVE-2020-PFPSN

(cherry picked from commit 93b6044e1636404f3463f3e1113098742e295542)
(cherry picked from commit 4e59a5d5c448e1fcdcbead268ffe6561adf0224d)
---

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index ba9cc1c12..07fba9c23 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -269,6 +269,10 @@ PP/03 Impose security length checks on various command-line options.
 PP/04 Fix Linux security issue CVE-2020-SLCWD and guard against PATH_MAX
       better.  Reported by Qualys.
 
+PP/05 Fix security issue CVE-2020-PFPSN and guard against cmdline invoker
+      providing a particularly obnoxious sender full name.
+      Reported by Qualys.
+
 
 Exim version 4.94
 -----------------
diff --git a/src/src/parse.c b/src/src/parse.c
index 18a6df198..7dfb9a7eb 100644
--- a/src/src/parse.c
+++ b/src/src/parse.c
@@ -1129,9 +1129,17 @@ while (s < end)
             {
             if (ss >= end) ss--;
             *t++ = '(';
-            Ustrncpy(t, s, ss-s);
-            t += ss-s;
-            s = ss;
+            if (ss < s)
+              {
+              /* Someone has ended the string with "<punct>(". */
+              ss = s;
+              }
+            else
+              {
+              Ustrncpy(t, s, ss-s);
+              t += ss-s;
+              s = ss;
+              }
             }
           }