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MIT krb5 Security Advisory 2010-002 Original release: 2010-03-23 Last update: 2010-03-23
Topic: denial of service in SPNEGO
CVE-2010-0628 VU#839413 denial of service in SPNEGO
CVSSv2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C/E:POC/RL:OF/RC:C
CVSSv2 Base Score: 7.8
Access Vector: Network Access Complexity: Low Authentication: None Confidentiality Impact: None Integrity Impact: None Availability Impact: Complete
CVSSv2 Temporal Score: 6.1
Exploitability: Proof-of-Concept Remediation Level: Official Fix Report Confidence: Confirmed
In MIT krb5 releases krb5-1.7 and later, the SPNEGO GSS-API mechanism can experience an assertion failure when receiving certain invalid messages. This can cause a GSS-API application to crash.
This is an implementation vulnerability in MIT krb5, and not a vulnerability in the Kerberos protocol.
An unauthenticated remote attacker could cause a GSS-API application, including the Kerberos administration daemon (kadmind) to crash.
kadmind in MIT releases krb5-1.7 and later
FTP daemon in MIT releases krb5-1.7 and later
Third-party software using the GSS-API library from MIT krb5 releases krb5-1.7 and later
MIT releases prior to krb5-1.7 did not contain the vulnerable code.
The upcoming krb5-1.7.2 and krb5-1.8.1 releases will contain fixes for this vulnerability.
Apply the patch available at
A PGP-signed patch is available at
This announcement is posted at:
This announcement and related security advisories may be found on the MIT Kerberos security advisory page at:
The main MIT Kerberos web page is at:
CVE: CVE-2010-0628 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-0628
CERT: VU#839413 http://www.kb.cert.org/vuls/id/839413
Thanks to Nalin Dahyabhai, Jan iankko Lieskovsky, and Zbysek Mraz (all from Red Hat) for discovering and reporting this vulnerability.
The MIT Kerberos Team security contact address is <email@example.com>. When sending sensitive information, please PGP-encrypt it using the following key:
pub 2048R/8B8DF501 2010-01-15 [expires: 2011-02-01] uid MIT Kerberos Team Security Contact <firstname.lastname@example.org>
A patch to fix CVE-2009-0845 interacted poorly with new functionality introduced in krb5-1.7. This allowed an error condition to occur where receiving an invalid packet could cause an assertion failure, crashing the program and causing denial of service.
When the spnego_gss_accept_sec_context() function (in src/lib/gssapi/spnego/spnego_mech.c) receives an invalid packet during the beginning of a GSS-API protocol exchange, it can set some internal state that tells it to send an error token without first creating a context handle, but some subsequently executed code contains a call to assert() that requires that the context handle be non-null.
2010-03-23 original release
Copyright (C) 2010 Massachusetts Institute of Technology -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (SunOS)
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