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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.031 (87.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 87.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.031 · newest: 0.031 · change: 0.000
Affected products
- Mozilla Firefox — versions unspecified, 56.0, 52.4.0
- Mozilla Firefox Esr — versions unspecified
- Mozilla Thunderbird — versions unspecified, 52.4.0
- Debian Linux — versions 7.0, 8.0, 9.0
Weakness classification (CWE)
References
- access.redhat.com/errata/RHSA-2017:2832 (vendor-advisory, Third Party Advisory)
- www.securityfocus.com/bid/101059 (VDB Entry, Third Party Advisory, vdb-entry)
- lists.debian.org/debian-lts-announce/2017/11/msg00000.html (mailing-list, Third Party Advisory)
- www.mozilla.org/security/advisories/mfsa2017-22/ (Vendor Advisory)
- bugzilla.mozilla.org/show_bug.cgi (Issue Tracking, Vendor Advisory)
- www.securitytracker.com/id/1039465 (VDB Entry, Third Party Advisory, vdb-entry)
- www.mozilla.org/security/advisories/mfsa2017-21/ (Vendor Advisory)
- www.debian.org/security/2017/dsa-4014 (vendor-advisory, Third Party Advisory)
- www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
- www.mozilla.org/security/advisories/mfsa2017-23/ (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.