CVE-2009-0845

CVE-2009-0845 is a medium-severity vulnerability in Mit Kerberos with a CVSS 2.0 base score of 5.0. 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-20.

Key facts

• Severity: Medium (CVSS 2.0 base score 5.0)
• EPSS exploit prediction: 6% (92nd percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-20
• Affected product: Mit Kerberos
• Published: 2009-03-27
• Last modified: 2026-06-16

Description

The spnego_gss_accept_sec_context function in lib/gssapi/spnego/spnego_mech.c in MIT Kerberos 5 (aka krb5) 1.5 through 1.6.3, when SPNEGO is used, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via invalid ContextFlags data in the reqFlags field in a negTokenInit token.

Frequently asked questions

What is CVE-2009-0845?

The spnego_gss_accept_sec_context function in lib/gssapi/spnego/spnego_mech.c in MIT Kerberos 5 (aka krb5) 1.5 through 1.6.3, when SPNEGO is used, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via invalid ContextFlags data in the reqFlags field in a negTokenInit token.

How severe is CVE-2009-0845?

CVE-2009-0845 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2009-0845 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0845?

CVE-2009-0845 primarily affects Mit Kerberos. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0845?

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

When was CVE-2009-0845 published?

CVE-2009-0845 was published on 2009-03-27 and last updated on 2026-06-16.

References

• http://krbdev.mit.edu/rt/Ticket/Display.html?user=guest&pass=guest&id=6402
• http://lists.apple.com/archives/security-announce/2009/May/msg00002.html
• http://secunia.com/advisories/34347
• http://secunia.com/advisories/34594
• http://secunia.com/advisories/34617
• http://secunia.com/advisories/34622
• http://secunia.com/advisories/34628
• http://secunia.com/advisories/34630
• http://secunia.com/advisories/34637
• http://secunia.com/advisories/34640
• http://secunia.com/advisories/34734
• http://secunia.com/advisories/35074
• http://security.gentoo.org/glsa/glsa-200904-09.xml
• http://src.mit.edu/fisheye/browse/krb5/trunk/src/lib/gssapi/spnego/spnego_mech.c?r1=21875&r2=22084
• http://src.mit.edu/fisheye/changelog/krb5/?cs=22084
• http://sunsolve.sun.com/search/document.do?assetkey=1-26-256728-1
• http://support.apple.com/kb/HT3549
• http://support.avaya.com/elmodocs2/security/ASA-2009-142.htm
• http://support.novell.com/docs/Readmes/InfoDocument/patchbuilder/readme_5047180.html
• http://support.novell.com/docs/Readmes/InfoDocument/patchbuilder/readme_5047181.html
• http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2009-001.txt
• http://wiki.rpath.com/Advisories:rPSA-2009-0058
• http://wiki.rpath.com/wiki/Advisories:rPSA-2009-0058
• http://www-01.ibm.com/support/docview.wss?uid=swg21396120
• http://www.kb.cert.org/vuls/id/662091
• http://www.mandriva.com/security/advisories?name=MDVSA-2009:082
• http://www.redhat.com/support/errata/RHSA-2009-0408.html
• http://www.securityfocus.com/archive/1/502526/100/0/threaded
• http://www.securityfocus.com/archive/1/502546/100/0/threaded
• http://www.securityfocus.com/bid/34257

Affected products (8)

• cpe:2.3:a:mit:kerberos:5-1.6.3:*:*:*:*:*:*:*
• cpe:2.3:a:mit:kerberos_5:1.5:*:*:*:*:*:*:*
• cpe:2.3:a:mit:kerberos_5:1.5.1:*:*:*:*:*:*:*
• cpe:2.3:a:mit:kerberos_5:1.5.2:*:*:*:*:*:*:*
• cpe:2.3:a:mit:kerberos_5:1.5.3:*:*:*:*:*:*:*
• cpe:2.3:a:mit:kerberos_5:1.6:*:*:*:*:*:*:*
• cpe:2.3:a:mit:kerberos_5:1.6.1:*:*:*:*:*:*:*
• cpe:2.3:a:mit:kerberos_5:1.6.2:*:*:*:*:*:*:*

More vulnerabilities in Mit Kerberos

• CVE-2009-4212 — Critical (CVSS 10.0): Multiple integer underflows in the (1) AES and (2) RC4 decryption functionality in the crypto library in MIT Kerberos 5…
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• CVE-2000-0389 — Critical (CVSS 10.0): Buffer overflow in krb_rd_req function in Kerberos 4 and 5 allows remote attackers to gain root privileges.
• CVE-2000-0390 — Critical (CVSS 10.0): Buffer overflow in krb425_conv_principal function in Kerberos 5 allows remote attackers to gain root privileges.
• CVE-2000-0391 — Critical (CVSS 10.0): Buffer overflow in krshd in Kerberos 5 allows remote attackers to gain root privileges.

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