HOMEVULNERABILITIESCVE-2021-3999
HIGH

CVE-2021-3999

CWE-193Published: August 24, 2022· Updated: Jun 17, 2026

7.8
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-3999 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Debian1 product(s)
debian linux
gnu1 product(s)
glibc
netapp13 product(s)
e-series performance analyzernfs plug-inontap select deploy administration utilityh300s firmwareh300sh500s firmwareh500sh700s firmwareh700sh410s firmwareh410sh410c firmware+1
Source: NVD CPE · 16 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://access.redhat.com/security/cve/CVE-2021-3999
ADVISORYhttps://bugzilla.redhat.com/show_bug.cgi?id=2024637
ADVISORYhttps://lists.debian.org/debian-lts-announce/2022/10/msg00021.html
ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2021-3999
ADVISORYhttps://security.netapp.com/advisory/ntap-20221104-0001/
ADVISORYhttps://sourceware.org/bugzilla/show_bug.cgi?id=28769
ADVISORYhttps://www.openwall.com/lists/oss-security/2022/01/24/4
ADVISORYhttps://access.redhat.com/security/cve/CVE-2021-3999
ADVISORYhttps://bugzilla.redhat.com/show_bug.cgi?id=2024637
ADVISORYhttps://lists.debian.org/debian-lts-announce/2022/10/msg00021.html
ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2021-3999
ADVISORYhttps://security.netapp.com/advisory/ntap-20221104-0001/
ADVISORYhttps://sourceware.org/bugzilla/show_bug.cgi?id=28769
ADVISORYhttps://www.openwall.com/lists/oss-security/2022/01/24/4

All References (16)

→
https://access.redhat.com/security/cve/CVE-2021-3999Third Party Advisory
→
https://bugzilla.redhat.com/show_bug.cgi?id=2024637Issue Tracking · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2022/10/msg00021.htmlMailing List · Third Party Advisory
→
https://security-tracker.debian.org/tracker/CVE-2021-3999Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20221104-0001/Third Party Advisory
→
https://sourceware.org/bugzilla/show_bug.cgi?id=28769Issue Tracking · Third Party Advisory
→
https://sourceware.org/git/gitweb.cgi?p=glibc.git%3Bh=23e0e8f5f1fb5ed150253d986ecccdc90c2dcd5e
→
https://www.openwall.com/lists/oss-security/2022/01/24/4Exploit · Mailing List · Third Party Advisory
→
https://access.redhat.com/security/cve/CVE-2021-3999Third Party Advisory
→
https://bugzilla.redhat.com/show_bug.cgi?id=2024637Issue Tracking · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2022/10/msg00021.htmlMailing List · Third Party Advisory
→
https://security-tracker.debian.org/tracker/CVE-2021-3999Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20221104-0001/Third Party Advisory
→
https://sourceware.org/bugzilla/show_bug.cgi?id=28769Issue Tracking · Third Party Advisory
→
https://sourceware.org/git/gitweb.cgi?p=glibc.git%3Bh=23e0e8f5f1fb5ed150253d986ecccdc90c2dcd5e

Quick Facts

CVE IDCVE-2021-3999
CVSS Score7.8 / 10
SeverityHIGH
WeaknessCWE-193
CISA KEVNo
Affected3 vendor(s)
PublishedAug 24, 2022

Related CVEs (CWE-193)

CVE-2025-54349
10.0
CVE-2024-10442
10.0
CVE-2018-8828
9.8
CVE-2022-34970
9.8
CVE-2004-0005
9.8
CVE-2003-0252
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-3999 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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