How severe is CVE-2009-1956?

CVE-2009-1956 has a CVSS 2.0 base score of 6.4, rated medium severity.

Is CVE-2009-1956 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 12% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-1956?

CVE-2009-1956 primarily affects Apache Apr-util. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-1956?

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

When was CVE-2009-1956 published?

CVE-2009-1956 was published on 2009-06-08 and last updated on 2026-06-16.

CVE-2009-1956

CVE-2009-1956 is a medium-severity vulnerability in Apache Apr-util with a CVSS 2.0 base score of 6.4. Its EPSS exploit-prediction score of 12% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-189.

Key facts

Severity: Medium (CVSS 2.0 base score 6.4)
EPSS exploit prediction: 12% (96th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-189
Affected product: Apache Apr-util
Published: 2009-06-08
Last modified: 2026-06-16

Description

Off-by-one error in the apr_brigade_vprintf function in Apache APR-util before 1.3.5 on big-endian platforms allows remote attackers to obtain sensitive information or cause a denial of service (application crash) via crafted input.

Frequently asked questions

What is CVE-2009-1956?: Off-by-one error in the apr_brigade_vprintf function in Apache APR-util before 1.3.5 on big-endian platforms allows remote attackers to obtain sensitive information or cause a denial of service (application crash) via crafted input.
How severe is CVE-2009-1956?: CVE-2009-1956 has a CVSS 2.0 base score of 6.4, rated medium severity.
Is CVE-2009-1956 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 12% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-1956?: CVE-2009-1956 primarily affects Apache Apr-util. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-1956?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-1956 published?: CVE-2009-1956 was published on 2009-06-08 and last updated on 2026-06-16.

References

Affected products (6)

cpe:2.3:a:apache:apr-util:*:*:*:*:*:*:*:*
cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:6.06:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:8.04:*:*:*:-:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:8.10:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:9.04:*:*:*:*:*:*:*

More vulnerabilities in Apache Apr-util

CVE-2009-2412 — Critical (CVSS 10.0): Multiple integer overflows in the Apache Portable Runtime (APR) library and the Apache Portable Utility library (aka…
CVE-2009-1955 — High (CVSS 7.5): The expat XML parser in the apr_xml_* interface in xml/apr_xml.c in Apache APR-util before 1.3.7, as used in the…
CVE-2010-1623 — Medium (CVSS 5.0): Memory leak in the apr_brigade_split_line function in buckets/apr_brigade.c in the Apache Portable Runtime Utility…
CVE-2011-1928 — Medium (CVSS 4.3): The fnmatch implementation in apr_fnmatch.c in the Apache Portable Runtime (APR) library 1.4.3 and 1.4.4, and the…
CVE-2009-0023 — Medium (CVSS 4.3): The apr_strmatch_precompile function in strmatch/apr_strmatch.c in Apache APR-util before 1.3.5 allows remote attackers…

All CVEs affecting Apache Apr-util →

Other CWE-189 (Numeric Errors) vulnerabilities

CVE-2015-8396 — Critical (CVSS 10.0): Integer overflow in the ImageRegionReader::ReadIntoBuffer function in…
CVE-2015-7205 — Critical (CVSS 10.0): Integer underflow in the RTPReceiverVideo::ParseRtpPacket function in Mozilla Firefox before 43.0 and Firefox ESR 38.x…
CVE-2015-6575 — Critical (CVSS 10.0): SampleTable.cpp in libstagefright in Android before 5.1.1 LMY48I does not properly consider integer promotion, which…
CVE-2015-3864 — Critical (CVSS 10.0): Integer underflow in the MPEG4Extractor::parseChunk function in MPEG4Extractor.cpp in libstagefright in mediaserver in…
CVE-2015-3836 — Critical (CVSS 10.0): The Parse_wave function in arm-wt-22k/lib_src/eas_mdls.c in the Sonivox DLS-to-EAS converter in Android before 5.1.1…
CVE-2015-3834 — Critical (CVSS 10.0): Multiple integer overflows in the BnHDCP::onTransact function in media/libmedia/IHDCP.cpp in libstagefright in Android…

Browse all CWE-189 (Numeric Errors) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

222.99.52.202 (ipv4-addr)
41.224.62.206 (ipv4-addr)
218.4.156.254 (ipv4-addr)
171.100.156.38 (ipv4-addr)