HOMEVULNERABILITIESCVE-2021-45960
HIGH

CVE-2021-45960

CWE-682Published: January 1, 2022· Updated: Jun 17, 2026

8.8
CVSS v3.1

Official Description

In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

NVD Source

Technical Analysis

CVE-2021-45960 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

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 8.8.

CVSS v3.1 Vector Breakdown

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

Affected Vendors & Products

Debian1 product(s)
debian linux
libexpat_project1 product(s)
libexpat
netapp4 product(s)
active iq unified managerhci baseboard management controlleroncommand workflow automationsolidfire \& hci management node
siemens1 product(s)
sinema remote connect server
tenable1 product(s)
nessus
Source: NVD CPE · 11 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

PATCHhttps://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdf
PATCHhttps://github.com/libexpat/libexpat/issues/531
PATCHhttps://github.com/libexpat/libexpat/pull/534
PATCHhttps://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdf
PATCHhttps://github.com/libexpat/libexpat/issues/531
PATCHhttps://github.com/libexpat/libexpat/pull/534
ADVISORYhttp://www.openwall.com/lists/oss-security/2022/01/17/3
ADVISORYhttps://bugzilla.mozilla.org/show_bug.cgi?id=1217609
ADVISORYhttps://security.gentoo.org/glsa/202209-24
ADVISORYhttps://security.netapp.com/advisory/ntap-20220121-0004/
ADVISORYhttps://www.debian.org/security/2022/dsa-5073
ADVISORYhttps://www.tenable.com/security/tns-2022-05
ADVISORYhttp://www.openwall.com/lists/oss-security/2022/01/17/3
ADVISORYhttps://bugzilla.mozilla.org/show_bug.cgi?id=1217609
ADVISORYhttps://security.gentoo.org/glsa/202209-24
ADVISORYhttps://security.netapp.com/advisory/ntap-20220121-0004/
ADVISORYhttps://www.debian.org/security/2022/dsa-5073
ADVISORYhttps://www.tenable.com/security/tns-2022-05

All References (18)

→
http://www.openwall.com/lists/oss-security/2022/01/17/3Exploit · Mailing List · Third Party Advisory
→
https://bugzilla.mozilla.org/show_bug.cgi?id=1217609Issue Tracking · Permissions Required · Third Party Advisory
→
https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdfPatch · Third Party Advisory
→
https://github.com/libexpat/libexpat/issues/531Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://github.com/libexpat/libexpat/pull/534Patch · Third Party Advisory
→
https://security.gentoo.org/glsa/202209-24Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20220121-0004/Third Party Advisory
→
https://www.debian.org/security/2022/dsa-5073Issue Tracking · Third Party Advisory
→
https://www.tenable.com/security/tns-2022-05Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2022/01/17/3Exploit · Mailing List · Third Party Advisory
→
https://bugzilla.mozilla.org/show_bug.cgi?id=1217609Issue Tracking · Permissions Required · Third Party Advisory
→
https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdfPatch · Third Party Advisory
→
https://github.com/libexpat/libexpat/issues/531Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://github.com/libexpat/libexpat/pull/534Patch · Third Party Advisory
→
https://security.gentoo.org/glsa/202209-24Third Party Advisory

Quick Facts

CVE IDCVE-2021-45960
CVSS Score8.8 / 10
SeverityHIGH
WeaknessCWE-682
CISA KEVNo
Affected5 vendor(s)
PublishedJan 1, 2022

Related CVEs (CWE-682)

CVE-2020-0221
9.8
CVE-2018-8319
9.8
CVE-2024-36736
9.8
CVE-2021-44847
9.8
CVE-2026-1229
9.8
CVE-2022-30600
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-45960 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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