Buffer overflow in Mozilla Firefox
CVE-2019-9792
The IonMonkey just-in-time (JIT) compiler can leak an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. This magic value can then be used by JavaScript to achieve memory corruption, which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.132 (96.3th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 96th percentile — 96.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.132 · newest: 0.132 · change: 0.000
Affected products
- Mozilla Firefox — versions unspecified
- Mozilla Firefox Esr — versions unspecified
- Mozilla Thunderbird — versions unspecified
- Red Hat Enterprise Linux — versions 8.0
- Red Hat Enterprise Linux Eus — versions 8.1, 8.2, 8.4
- Red Hat Enterprise Linux Server Aus — versions 8.2, 8.4
- Red Hat Enterprise Linux Server Tus — versions 8.2, 8.4
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.mozilla.org/security/advisories/mfsa2019-07/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2019-08/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2019-11/ (Vendor Advisory)
- bugzilla.mozilla.org/show_bug.cgi (Exploit, Issue Tracking, Vendor Advisory)
- access.redhat.com/errata/RHSA-2019:0966 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2019:1144 (vendor-advisory, Third Party Advisory)
- packetstormsecurity.com/files/153106/Spidermonkey-IonMonkey-JS_OPTIMIZED_OUT-Va… (Exploit, VDB Entry, Third Party Advisory)
Frequently asked questions
- What is CVE-2019-9792?
- CVE-2019-9792 is a critical-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2019-04-26.
- How severe is CVE-2019-9792?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2019-9792 known to be exploited?
- 7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.