CVE-2011-4623: Buffer Overflow

Published Dec 22, 2011

Updated

An integer signedness error, leading to heap based buffer overflow was found in the way the imfile module of rsyslog, an enhanced system logging and kernel message trapping daemon, processed text files larger than 64 KB. When the imfile rsyslog module was enabled, a local attacker could use this flaw to cause denial of service (rsyslogd daemon hang) via specially-crafted message, to be logged.

Upstream bug report: [1] http://bugzilla.adiscon.com/showbug.cgi?id=221

Upstream patch: [2] http://git.adiscon.com/?p=rsyslog.git;a=commit;h=6bad782f154b7f838c7371bf99c13f6dc4ec4101

Other sources

Integer overflow in the rsCStrExtendBuf function in runtime/stringbuf.c in the imfile module in rsyslog 4.x before 4.6.6, 5.x before 5.7.4, and 6.x before 6.1.4 allows local users to cause a denial of service (daemon hang) via a large file, which triggers a heap-based buffer overflow.

— MITRE

Affected Software

72 affected components

rsyslog Rsyslog=4.5.6

rsyslog Rsyslog=4.1.2

rsyslog Rsyslog=4.5.1

rsyslog Rsyslog=4.6.3

rsyslog Rsyslog=4.5.2

rsyslog Rsyslog=4.1.1

rsyslog Rsyslog=4.4.2

rsyslog Rsyslog=4.6.4

rsyslog Rsyslog=4.5.4

rsyslog Rsyslog=4.3.2

rsyslog Rsyslog=4.1.3

rsyslog Rsyslog=4.5.3

rsyslog Rsyslog=4.6.1

rsyslog Rsyslog=4.1.0

rsyslog Rsyslog=4.5.8

rsyslog Rsyslog=4.1.5

rsyslog Rsyslog=4.3.0

rsyslog Rsyslog=4.6.2

rsyslog Rsyslog=4.5.5

rsyslog Rsyslog=4.4.0

rsyslog Rsyslog=4.6.0

rsyslog Rsyslog=4.5.0

rsyslog Rsyslog=4.1.7

rsyslog Rsyslog=4.2.0

rsyslog Rsyslog=4.4.1

rsyslog Rsyslog=4.3.1

rsyslog Rsyslog=4.6.5

rsyslog Rsyslog=4.1.6

rsyslog Rsyslog=4.1.4

rsyslog Rsyslog=4.5.7

rsyslog Rsyslog=5.5.6

rsyslog Rsyslog=5.5.7

rsyslog Rsyslog=5.4.2

rsyslog Rsyslog=5.5.0

rsyslog Rsyslog=5.5.4

rsyslog Rsyslog=5.1.6

rsyslog Rsyslog=5.5.1

rsyslog Rsyslog=5.6.1

rsyslog Rsyslog=5.3.6

rsyslog Rsyslog=5.1.1

rsyslog Rsyslog=5.6.4

rsyslog Rsyslog=5.1.4

rsyslog Rsyslog=5.5.3

rsyslog Rsyslog=5.6.2

rsyslog Rsyslog=5.6.0

rsyslog Rsyslog=5.6.5

rsyslog Rsyslog=5.1.0

rsyslog Rsyslog=5.1.5

rsyslog Rsyslog=5.4.0

rsyslog Rsyslog=5.7.2

rsyslog Rsyslog=5.3.1

rsyslog Rsyslog=5.1.2

rsyslog Rsyslog=5.2.0

rsyslog Rsyslog=5.3.7

rsyslog Rsyslog=5.2.2

rsyslog Rsyslog=5.3.3

rsyslog Rsyslog=5.3.2

rsyslog Rsyslog=5.6.3

rsyslog Rsyslog=5.5.2

rsyslog Rsyslog=5.2.1

rsyslog Rsyslog=5.4.1

rsyslog Rsyslog=5.7.0

rsyslog Rsyslog=5.7.3

rsyslog Rsyslog=5.1.3

rsyslog Rsyslog=5.5.5

rsyslog Rsyslog=5.3.4

rsyslog Rsyslog=5.7.1

rsyslog Rsyslog=5.3.5

rsyslog Rsyslog=6.1.1

rsyslog Rsyslog=6.1.0

rsyslog Rsyslog=6.1.3

rsyslog Rsyslog=6.1.2

Remediation

Patch Available

http://www.ubuntu.com/usn/USN-1338-1

Event History

Dec 22, 2011

Data Sourced

12:09 PM

DescriptionSeverityAffected Software

Sep 25, 2012

CVE Published

via MITRE·11:00 PM

Data Sourced

via MITRE·11:00 PM

Description

Frequently Asked Questions

What is the severity of CVE-2011-4623?

CVE-2011-4623 is rated as high severity due to the potential for a local attacker to exploit the heap-based buffer overflow.

How do I fix CVE-2011-4623?

To mitigate CVE-2011-4623, update the rsyslog to a version that has patched this vulnerability.

What software versions are affected by CVE-2011-4623?

CVE-2011-4623 affects several versions of rsyslog, including 4.1.x through 5.7.x before the patching.

What type of vulnerability is CVE-2011-4623?

CVE-2011-4623 is an integer signedness error resulting in a heap-based buffer overflow.

Can CVE-2011-4623 be exploited remotely?

CVE-2011-4623 requires local access, thus it cannot be exploited remotely without prior system access.