← Vulnerability feed

Vulnerability record · CVE-2021-3696 · published 6 July 2022

CVE-2021-3696: Gnu grub2 out-of-bounds write vulnerability

Gnu · Grub2

A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may lead to data corruption in the heap space. Confidentiality, Integrity and Availablity impact may be considered Low as it's very complex to an attacker control the encoding and positioning of corrupted Huffman entries to achieve results such as arbitrary code execution and/or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.

4.5 CVSS 3.1 Medium EPSS 0.47% · top 61.6% CWE-787 · Out-of-bounds write
4.5CVSS 3.1 base score, v2 6.9
0.47%EPSS exploitation probability, 30 days
NoNot in CISA KEV
13Affected product versions listed by NVD
6References
17 Jun 2026Last modified by NVD

Description

A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may lead to data corruption in the heap space. Confidentiality, Integrity and Availablity impact may be considered Low as it's very complex to an attacker control the encoding and positioning of corrupted Huffman entries to achieve results such as arbitrary code execution and/or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.

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

Affected products

13 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://bugzilla.redhat.com/show_bug.cgi?id=1991686 Issue TrackingThird Party Advisory
https://security.gentoo.org/glsa/202209-12 Third Party Advisory
https://security.netapp.com/advisory/ntap-20220930-0001/ Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1991686 Issue TrackingThird Party Advisory
https://security.gentoo.org/glsa/202209-12 Third Party Advisory
https://security.netapp.com/advisory/ntap-20220930-0001/ Third Party Advisory

Track CVE-2021-3696 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2019-11043PHP-FPM buffer overflow enables remote code executionPHP-FPM in certain configurations writes past allocated buffers into FCGI protocol data space, an out-of-bounds write (CWE-787, CWE-120). It affects …KEVEPSS 100%analysed9.8CVE-2018-14667RichFaces Framework EL injection enables unauthenticated remote code executionRichFaces Framework 3.X through 3.3.4 is vulnerable to Expression Language injection through the UserResource resource. A remote, unauthenticated att…KEVEPSS 74%analysed9.8CVE-2014-7169GNU Bash environment variable function parsing command injection (Shellshock variant)GNU Bash through 4.3 bash43-025 processes trailing strings after malformed function definitions in environment variable values, allowing command inje…KEVEPSS 100%analysed9.8CVE-2014-6271GNU Bash environment variable command injection (ShellShock)GNU Bash through 4.3 processes trailing strings after function definitions in environment variable values, allowing injected commands to run when Bas…KEVEPSS 100%analysed9.6CVE-2020-15999FreeType heap buffer overflow in Chrome via crafted HTML pageFreeType contains a heap buffer overflow reachable through a crafted HTML page in Google Chrome prior to 86.0.4240.111. The flaw is an out-of-bounds …KEVEPSS 44%analysed9.0CVE-2021-40438Apache HTTP Server mod_proxy SSRF via crafted URI pathA crafted request URI path can make mod_proxy forward the request to an origin server chosen by the remote user, an SSRF flaw in Apache HTTP Server 2…KEVEPSS 100%analysed8.8CVE-2025-31277Apple WebKit memory corruption via malicious web contentApple WebKit fails to handle memory correctly when processing crafted web content, leading to memory corruption across Safari, iOS, iPadOS, macOS, tv…KEVEPSS 1.6%analysed8.8CVE-2023-5217libvpx VP8 encoding heap buffer overflow exploited via crafted HTMLA heap buffer overflow in the VP8 encoder in libvpx affects Google Chrome before 117.0.5938.132 and libvpx 1.13.1, and is reachable through a crafted…KEVEPSS 49%analysed

Source: NIST National Vulnerability Database (record CVE-2021-3696), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.