How severe is CVE-2011-1951?

CVE-2011-1951 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2011-1951 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2011-1951?

CVE-2011-1951 affects Oneidentity Syslog-ng. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2011-1951?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2011-1951 published?

CVE-2011-1951 was published on 2011-07-11 and last updated on 2026-06-16.

CVE-2011-1951

CVE-2011-1951 is a medium-severity vulnerability in Oneidentity Syslog-ng with a CVSS 2.0 base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-399.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 2% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-399
Affected product: Oneidentity Syslog-ng
Published: 2011-07-11
Last modified: 2026-06-16

Description

lib/logmatcher.c in Balabit syslog-ng before 3.2.4, when the global flag is set and when using PCRE 8.12 and possibly other versions, allows remote attackers to cause a denial of service (memory consumption) via a message that does not match a regular expression.

Frequently asked questions

What is CVE-2011-1951?: lib/logmatcher.c in Balabit syslog-ng before 3.2.4, when the global flag is set and when using PCRE 8.12 and possibly other versions, allows remote attackers to cause a denial of service (memory consumption) via a message that does not match a regular expression.
How severe is CVE-2011-1951?: CVE-2011-1951 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2011-1951 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-1951?: CVE-2011-1951 affects Oneidentity Syslog-ng. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2011-1951?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2011-1951 published?: CVE-2011-1951 was published on 2011-07-11 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:oneidentity:syslog-ng:*:*:*:*:*:*:*:*

More vulnerabilities in Oneidentity Syslog-ng

CVE-2008-5110 — Critical (CVSS 9.3): syslog-ng does not call chdir when it calls chroot, which might allow attackers to escape the intended jail. NOTE: this…
CVE-2020-8019 — High (CVSS 7.7): A UNIX Symbolic Link (Symlink) Following vulnerability in the packaging of syslog-ng of SUSE Linux Enterprise Debuginfo…
CVE-2024-47619 — High (CVSS 7.5): syslog-ng is an enhanced log daemo. Prior to version 4.8.2, `tls_wildcard_match()` matches on certificates such as…
CVE-2022-38725 — High (CVSS 7.5): An integer overflow in the RFC3164 parser in One Identity syslog-ng 3.0 through 3.37 allows remote attackers to cause a…
CVE-2002-1200 — High (CVSS 7.5): Balabit Syslog-NG 1.4.x before 1.4.15, and 1.5.x before 1.5.20, when using template filenames or output, does not…
CVE-2011-0343 — Medium (CVSS 6.9): Balabit syslog-ng 2.0, 3.0, 3.1, 3.2 OSE and PE, when running on FreeBSD or HP-UX, does not properly perform cast…

All CVEs affecting Oneidentity Syslog-ng →

Other CWE-399 (Resource Management Errors) vulnerabilities

CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
CVE-2015-0339 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2015-0335 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2015-0333 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2014-4121 — Critical (CVSS 10.0): Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 does not properly parse internationalized…
CVE-2014-0560 — Critical (CVSS 10.0): Use-after-free vulnerability in Adobe Reader and Acrobat 10.x before 10.1.12 and 11.x before 11.0.09 on Windows and OS…

Browse all CWE-399 (Resource Management Errors) vulnerabilities →