Quantum Secular Labs / Blog / Advisories

CVE-2017-5443: Mozilla Firefox: Buffer overflow

CVE-2017-5443 is rated critical with a CVSS v3.0 base score of 9.8 and affects Mozilla Firefox, along with 7 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

An out-of-bounds write vulnerability while decoding improperly formed BinHex format archives. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
Attack complexity: Low. No special conditions; the attack can be repeated reliably.
Privileges required: None. No account or prior access is needed.
User interaction: None. No action from any user is needed.
Scope: Unchanged. Impact stays within the vulnerable component.
Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-787: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

Affected products

Mozilla Firefox: before 45.9.0; before 53.0; 52.0
Mozilla Thunderbird: before 52.1.0
Debian Linux: 9.0
Red Hat Enterprise Linux: 6.0; 7.0
Red Hat Enterprise Linux Desktop: 6.0; 7.0
Red Hat Enterprise Linux Server: 6.0; 7.0
Red Hat Enterprise Linux Server Aus: 7.3; 7.4
Red Hat Enterprise Linux Server Eus: 7.3; 7.4; 7.5
Red Hat Enterprise Linux Workstation: 6.0; 7.0