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CVE-2021-40633

27
FAUCET Score

CVE-2021-40633 is a memory leak vulnerability (CWE-401) in giflib 5.1.4's gif2rgb utility, allowing remote attackers to trigger an out-of-memory exception or denial of service via a specially crafted GIF file. With a CVSS score of 8.8 (High), this vulnerability can be exploited remotely with low attack complexity, requiring user interaction, and potentially leading to high impact on confidentiality, integrity, and availability. There is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
5.1.4CPE matchmatch criteria
cpe:2.3:a:giflib_project:giflib:5.1.4:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.53%
Probability of exploitation in next 30 days
EPSS Percentile
72.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0153 is in the 71st percentile among its peer group of 14,848 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.2 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.1 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (4)

microsoftpatch availablevia msrc
Product: 19085-17084Fixed in: 5.2.1-10
microsoftpatch availablevia msrc
Product: azl3 giflib 5.2.1-10 on Azure Linux 3.0Fixed in: 5.2.1-10
nodejspatch availablevia llm_extracted
View patch
pjsippatch availablevia llm_extracted
View patch

Vendor Advisories (4)

nodejsllm-nodejs-302528ae26f0d946CRITICAL

HP ThinPro 8.1 SP4 Security Updates

Oct 29, 2024
pjsipllm-pjsip-7ba3ec379210ac70CRITICAL

HP ThinPro 8.1 SP4 Security Updates

Oct 29, 2024
microsoft2022-Jun/CVE-2021-40633Important

A memory leak (out-of-memory) in gif2rgb in util/gif2rgb.c in giflib 5.1.4 allows remote attackers trigger an out of memory exception or denial of service via a gif format file.

Jun 14, 2022
redhatCVE-2021-40633Important

gif2rgb: gif2rgb memory leak

Jun 14, 2022

References

sourceforge.net / p/giflib/bugs/157
ExploitIssue TrackingThird Party Advisory