Buffer overflow in Mozilla Firefox

CVE-2021-23983

By causing a transition on a parent node by removing a CSS rule, an invalid property for a marker could have been applied, resulting in memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 87.

Vulnerability class: Buffer Overflow

EPSS: 0.007 (50.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-23983?
CVE-2021-23983 is a medium-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Write. CVSS score: 6.5/10. Published 2021-03-31.
How severe is CVE-2021-23983?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2021-23983 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.