Out-of-bounds Read in Mozilla Firefox
CVE-2020-6806
By carefully crafting promise resolutions, it was possible to cause an out-of-bounds read off the end of an array resized during script execution. This could have led to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.026 (84.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 85th percentile — 84.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.026 · newest: 0.026 · change: 0.000
Affected products
- Mozilla Firefox — versions unspecified
- Mozilla Firefox Esr — versions unspecified
- Mozilla Firefox Esr
- Mozilla Thunderbird — versions unspecified
- Canonical Ubuntu Linux — versions 16.04, 18.04, 19.10
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.mozilla.org/security/advisories/mfsa2020-08/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2020-10/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2020-09/ (Vendor Advisory)
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking)
- usn.ubuntu.com/4328-1/ (vendor-advisory, Third Party Advisory)
- usn.ubuntu.com/4335-1/ (vendor-advisory, Third Party Advisory)
- packetstormsecurity.com/files/157524/Firefox-js-ReadableStreamCloseInternal-Out… (VDB Entry, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-6806?
- CVE-2020-6806 is a high-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Read. CVSS score: 8.8/10. Published 2020-03-25.
- How severe is CVE-2020-6806?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2020-6806 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.