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Full vulnerability report · 2021
CVE-2021-45261High confidence

An Invalid Pointer vulnerability exists in GNU patch 2.7 via the another_hunk function, which causes a Denial of Service

n/a · n/a

5.5MediumCVSS 3.1
Recommended action
Within 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivepatchUnder evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-32041

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
01

What, why and how

An Invalid Pointer vulnerability exists in GNU patch 2.7 via the another_hunk function, which causes a Denial of Service.

What

An Invalid Pointer vulnerability exists in GNU patch 2.7 via the another_hunk function, which causes a Denial of Service.

Why

The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.

How

An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may disrupt the affected service.

What

An Invalid Pointer vulnerability exists in GNU patch 2.7 via the another_hunk function, which causes a Denial of Service.

Why

The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.

How

An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
local access → Release of Invalid Pointer or Reference → disrupt the affected service
Attack surface
Local
Privileges required
None: unauthenticated exploitation is possible
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-763 ↗

CWE-763: Release of Invalid Pointer or Reference. The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
UnauthenticatedDenial of serviceCWE-763Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2026-0304patch: Schwachstelle ermöglicht Denial of Service

Ein lokaler Angreifer kann eine Schwachstelle in patch ausnutzen, um einen Denial of Service Angriff durchzuführen.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0326Multiples vulnérabilités dans les produits VMware

rg/CVERecord?id=CVE-2021-3714 Référence CVE CVE-2021-3735 https://www.cve.org/CVERecord?id=CVE-2021-3735 Référence CVE CVE-2021-3773 https://www.cve.org/CVERecord?id=CVE-2021-3773 Référence CVE CVE-2021-3826 https://www.cve.org/CVERecord?id=CVE-2021-3826 Référence CVE CVE-2021-3864 https://www.cve.org/CVERecord?id=CVE-2021-3864 Référence CVE CVE-2021-4095 https://www.cve.org/CVERecord?id=CVE-2021-4095 Référence CVE CVE-2021-42771 https://www.cve.org/CVERecord?id=CVE-2021-42771 Référence CVE CVE-2021-44532 https://www.cve.org/CVERecord?id=CVE-2021-44532 Référence CVE CVE-2021-44534 https://www.cve.org/CVERecord?id=CVE-2021-44534 Référence CVE CVE-2021-45261 https://www.cve.org/CVERecord?id=CVE-2021-45261 Référence CVE CVE-2021-46195 https://www.cve.org/CVERecord?id=CVE-2021-46195 Référence CVE CVE-2021-47432 https://www.cve.org/CVERecord?id=CVE-2021-47432 Référence CVE CVE-2021-47658 https://www.cve.org/CVERecord?id=CVE-2021-47658 Référence CVE CVE-2022-0400 https://www.cve.org/CVERecord?id=CVE-2022-0400 Référence CVE CVE-2022-0480 https://www.cve.org/CVERecord?id=CVE-2022-0480 Référence CVE CVE-2022-0987 https://www.cve.org/CVERecord?id=CVE-2022-0987 Référence CVE CVE-2022-1205 https://www.cve.org/CVERecord?id=CVE-2022-1205 Référence CVE CVE-2022-1247 https://www.cve.org/CVERecord?id=CVE-2022-

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0316Multiples vulnérabilités dans les produits VMware

rg/CVERecord?id=CVE-2021-3714 Référence CVE CVE-2021-3735 https://www.cve.org/CVERecord?id=CVE-2021-3735 Référence CVE CVE-2021-3773 https://www.cve.org/CVERecord?id=CVE-2021-3773 Référence CVE CVE-2021-3826 https://www.cve.org/CVERecord?id=CVE-2021-3826 Référence CVE CVE-2021-3864 https://www.cve.org/CVERecord?id=CVE-2021-3864 Référence CVE CVE-2021-4095 https://www.cve.org/CVERecord?id=CVE-2021-4095 Référence CVE CVE-2021-42771 https://www.cve.org/CVERecord?id=CVE-2021-42771 Référence CVE CVE-2021-44532 https://www.cve.org/CVERecord?id=CVE-2021-44532 Référence CVE CVE-2021-44534 https://www.cve.org/CVERecord?id=CVE-2021-44534 Référence CVE CVE-2021-45261 https://www.cve.org/CVERecord?id=CVE-2021-45261 Référence CVE CVE-2021-46195 https://www.cve.org/CVERecord?id=CVE-2021-46195 Référence CVE CVE-2021-47432 https://www.cve.org/CVERecord?id=CVE-2021-47432 Référence CVE CVE-2021-47658 https://www.cve.org/CVERecord?id=CVE-2021-47658 Référence CVE CVE-2022-0400 https://www.cve.org/CVERecord?id=CVE-2022-0400 Référence CVE CVE-2022-0480 https://www.cve.org/CVERecord?id=CVE-2022-0480 Référence CVE CVE-2022-0987 https://www.cve.org/CVERecord?id=CVE-2022-0987 Référence CVE CVE-2022-1205 https://www.cve.org/CVERecord?id=CVE-2022-1205 Référence CVE CVE-2022-1247 https://www.cve.org/CVERecord?id=CVE-2022-

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0585Multiples vulnérabilités dans VMware Tanzu

.cve.org/CVERecord?id=CVE-2021-3927 Référence CVE CVE-2021-3928 https://www.cve.org/CVERecord?id=CVE-2021-3928 Référence CVE CVE-2021-3968 https://www.cve.org/CVERecord?id=CVE-2021-3968 Référence CVE CVE-2021-3973 https://www.cve.org/CVERecord?id=CVE-2021-3973 Référence CVE CVE-2021-3974 https://www.cve.org/CVERecord?id=CVE-2021-3974 Référence CVE CVE-2021-4136 https://www.cve.org/CVERecord?id=CVE-2021-4136 Référence CVE CVE-2021-4166 https://www.cve.org/CVERecord?id=CVE-2021-4166 Référence CVE CVE-2021-4173 https://www.cve.org/CVERecord?id=CVE-2021-4173 Référence CVE CVE-2021-4187 https://www.cve.org/CVERecord?id=CVE-2021-4187 Référence CVE CVE-2021-45261 https://www.cve.org/CVERecord?id=CVE-2021-45261 Référence CVE CVE-2022-0213 https://www.cve.org/CVERecord?id=CVE-2022-0213 Référence CVE CVE-2022-0351 https://www.cve.org/CVERecord?id=CVE-2022-0351 Référence CVE CVE-2022-1616 https://www.cve.org/CVERecord?id=CVE-2022-1616 Référence CVE CVE-2022-1619 https://www.cve.org/CVERecord?id=CVE-2022-1619 Référence CVE CVE-2022-1620 https://www.cve.org/CVERecord?id=CVE-2022-1620 Référence CVE CVE-2022-1674 https://www.cve.org/CVERecord?id=CVE-2022-1674 Référence CVE CVE-2022-1720 https://www.cve.org/CVERecord?id=CVE-2022-1720 Référence CVE CVE-2022-1725 https://www.cve.org/CVERecord?id=CVE-2022-1725 R

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
n/a
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 22 Dec 2021 · Last source change 4 Aug 2024, 04:39 UTC · CWE-763 · Release of Invalid Pointer or Reference

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-32041
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2021-32041↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-45261 · cve.blacktree.nl