7.8

CVE-2021-3999: debian debian_linux Off-by-one Error

Modified
AliasesMGASA-2022-0052UBUNTU-CVE-2021-3999DEBIAN-CVE-2021-3999
Published 24-08-2022Last modified 14-10-2026

Vulnerability summary

CVE-2021-3999 is a high (CVSS 7.8) Off-by-one Error vulnerability in debian debian_linux. EPSS estimates a 0.81% chance of exploitation in the next 30 days, higher than 56.9% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Prioritisepublic exploit

Public exploit (reference, Date unknown)

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.81%
0%100%
Low · +0.06 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 12 · Related 10
DLA-3152-1OPENSUSE-SU-2022:0330-1OPENSUSE-SU-2024:11850-1RHSA-2022:0896SUSE-SU-2022:0330-1SUSE-SU-2022:0441-1

Timeline

  1. 24-08-2022
    PublishedVulnerability first disclosed.
  2. 14-10-2026
    Last modifiedVulnerability information updated.

Description

A flaw was found in glibc. An off-by-one buffer overflow and underflow in getcwd() may lead to memory corruption when the size of the buffer is exactly 1. A local attacker who can control the input buffer and size passed to getcwd() in a setuid program could use this flaw to potentially execute arbitrary code and escalate their privileges on the system.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.81%

Chance of exploitation in the next 30 days

Percentile

57%

Versus all other CVEs

30-day change

Increase +0.06 pp

From 0.75% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (openwall.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Netapp7 products
Debian2 products
Ubuntu2 products
  • eglibc< 2.19-0ubuntu6.15+esm3
  • glibc< 2.23-0ubuntu11.3+esm1 | < 2.27-3ubuntu1.5 | < 2.31-0ubuntu9.7
Gnu1 product
Mageia1 product
  • glibc< 2.32-25.mga8

5 vendors · 13 products

References

18 links
Show all 18 references