Quantum Secular Labs / Blog / Advisories

CVE-2009-0846: Mit Kerberos 5: Remote code execution

CVE-2009-0846 has a CVSS v2 base score of 10.0 (the maximum on that scale) and affects Mit Kerberos 5, along with 8 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

The asn1_decode_generaltime function in lib/krb5/asn.1/asn1_decode.c in the ASN.1 GeneralizedTime decoder in MIT Kerberos 5 (aka krb5) before 1.6.4 allows remote attackers to cause a denial of service (daemon crash) or possibly execute arbitrary code via vectors involving an invalid DER encoding that triggers a free of an uninitialized pointer.

Severity breakdown

CVSS v2.0 10.0: AV:N/AC:L/Au:N/C:C/I:C/A:C

Access vector: Network. Exploitable remotely over the network.
Access complexity: Low. No special conditions are required.
Authentication: None. No authentication is needed.
Confidentiality impact: Complete. Total information disclosure.
Integrity impact: Complete. Total loss of integrity.
Availability impact: Complete. Total shutdown of the component.

Underlying weakness

CWE-824: Access of Uninitialized Pointer

The product accesses or uses a pointer that has not been initialized.

Affected products

Mit Kerberos 5: before 1.6.4
Fedoraproject: 9; 10
Canonical Ubuntu Linux: 6.06; 7.10; 8.04; 8.10
Apple Mac OS X: before 10.5.7
Red Hat Enterprise Linux: 4.0
Red Hat Enterprise Linux Desktop: 3.0; 4.0
Red Hat Enterprise Linux Eus: 4.7
Red Hat Enterprise Linux Server: 2.0; 3.0; 4.0
Red Hat Enterprise Linux Workstation: 2.0; 3.0; 4.0