Use After Free in Mozilla Firefox
CVE-2017-7805
During TLS 1.2 exchanges, handshake hashes are generated which point to a message buffer. This saved data is used for later messages but in some cases, the handshake transcript can exceed the space available in the current buffer, causing the allocation of a new buffer. This leaves a pointer pointing to the old, freed buffer, resulting in a use-after-free when handshake hashes are then calculated afterwards. This can result in a potentially exploitable crash. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.
Vulnerability class: Use-After-Free
EPSS: 0.032 (86.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Mozilla Firefox — versions unspecified, 56.0, 52.4.0
- Mozilla Firefox Esr — versions unspecified
- Mozilla Thunderbird — versions unspecified, 52.4.0
- Debian Debian_linux — versions 7.0, 8.0, 9.0
Weakness classification (CWE)
References
- security@mozilla.org (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)
- security@mozilla.org (VDB Entry, Third Party Advisory, vdb-entry, x_refsource_BID)
- security@mozilla.org (mailing-list, x_refsource_MLIST, Third Party Advisory)
- security@mozilla.org (x_refsource_CONFIRM, Vendor Advisory)
- security@mozilla.org (x_refsource_CONFIRM, Issue Tracking, Vendor Advisory)
- security@mozilla.org (VDB Entry, Third Party Advisory, vdb-entry, x_refsource_SECTRACK)
- security@mozilla.org (x_refsource_CONFIRM, Vendor Advisory)
- security@mozilla.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- security@mozilla.org (x_refsource_CONFIRM)
- security@mozilla.org (x_refsource_CONFIRM, Vendor Advisory)
Frequently asked questions
- What is CVE-2017-7805?
- CVE-2017-7805 is a high-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 7.5/10. Published 2018-06-11.
- How severe is CVE-2017-7805?
- High severity. CVSS v3 base score is 7.5 out of 10.