CVE-2021-29977

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

1.00% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 62.7% of scored records. A rank, not a probability.

NVD base score

8.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-08-05 19:46Z5 YR AGO

Last updated

2024-08-03 22:24Z2 YR AGO

Reserved

2021-04-01

Assigning CNA

mozilla

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-787Out-of-bounds WriteBase

Data version

5.1

Document digest

6adb3208c488b0ee6d71683fb345ef524bb02b12fa6887d870c937b6fcc9b745

• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2021-28/x_refsource_MISC
• bugzilla.mozilla.orghttps://bugzilla.mozilla.org/buglist.cgi?bug_id=1665836%2C1686138%2C1704316%2C1706314%2C1709931%2C1712084%2C1712357%2C1714066x_refsource_MISC
• security.gentoo.orgGLSA-202202-03https://security.gentoo.org/glsa/202202-03vendor-advisoryx_refsource_GENTOO