SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-23997

Due to unexpected data type conversions, a use-after-free could have occurred when interacting with the font cache.

HIGH 8.8EPSS 0.82%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.82%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Due to unexpected data type conversions, a use-after-free could have occurred when interacting with the font cache. We presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox < 88.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
0.82% probability · 55th percentile
CISA KEV
Not listed
Weakness
CWE-681
Affected
mozilla/firefox
Source
security@mozilla.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.