CVE-2011-1764: High severity sa-exim vulnerability
Format string vulnerability in the dkimeximverifyfinish function in src/dkim.c in Exim before 4.76 might allow remote attackers to execute arbitrary code or cause a denial of service (daemon crash) via format string specifiers in data used in DKIM logging, as demonstrated by an identity field containing a % (percent) character.
Other sources
It was reported [1],[2] that Exim would improperly interpret '%' in a DKIM (DomainKeys Identified Mail) signature, which would get logged to the paniclog. It is possible that using '%n' in the DKIM signature could be used to verwrite stack data, which could cause Exim to crash.
DKIM support has been in Exim since version 4.70.
A fix has been pushed upstream [3].
[1] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=624670 [2] http://bugs.exim.org/showbug.cgi?id=1106 [3] http://git.exim.org/exim.git/commitdiff/337e3505b0e6cd4309db6bf6062b33fa56e06cf8
Statement:
Not vulnerable. This issue did not affect the versions of exim as shipped with Red Hat Enterprise Linux 4 or 5 as they did not include support for DKIM.
— Red Hat
Affected Software
Remediation
Patch Available
Patch Available
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2011-1764?
CVE-2011-1764 is classified as a critical vulnerability that allows remote attackers to potentially execute arbitrary code or cause a denial of service.
How do I fix CVE-2011-1764?
To fix CVE-2011-1764, upgrade Exim to version 4.76 or a later version which addresses the vulnerability.
Which versions of Exim are affected by CVE-2011-1764?
CVE-2011-1764 affects Exim versions prior to 4.76, including versions 4.75 and earlier.
Can CVE-2011-1764 lead to system compromise?
Yes, CVE-2011-1764 can lead to system compromise as it allows for remote code execution under certain conditions.
What type of vulnerability is CVE-2011-1764?
CVE-2011-1764 is classified as a format string vulnerability in the DKIM logging function of Exim.