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CVE-2012-4218: Mozilla Firefox: Use after free

CVE-2012-4218 has a CVSS v2 base score of 10.0 (the maximum on that scale) and affects Mozilla Firefox, along with 5 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

Use-after-free vulnerability in the BuildTextRunsScanner::BreakSink::SetBreaks function in Mozilla Firefox before 17.0, Thunderbird before 17.0, and SeaMonkey before 2.14 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via unspecified vectors.

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-416: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

Affected products

Mozilla Firefox: before 17.0
Mozilla Seamonkey: before 2.14
Mozilla Thunderbird: before 17.0
Canonical Ubuntu Linux: 10.04; 11.10; 12.04; 12.10
Opensuse: 11.4; 12.1; 12.2
Suse Linux Enterprise Desktop: 10 sp4; 11 sp2
Suse Linux Enterprise Server: 10 sp4; 11 sp2
Suse Linux Enterprise Software Development Kit: 11 sp2; 11 sp3