CVE-2021-43539 is a use-after-free vulnerability in Mozilla Firefox, Firefox ESR, and Thunderbird versions prior to 91.4.0 and 95, respectively. This flaw stems from incorrect handling of live pointers during WebAssembly (Wasm) instance calls, potentially leading to a crash. With a CVSS score of 8.8 (High), it is a network-exploitable vulnerability requiring user interaction, capable of causing high impact to confidentiality, integrity, and availability. While no public exploit code or active exploitation has been observed, the vulnerability has garnered some community discussion and media coverage, indicating awareness within the security community.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 95.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | ||
< 91.4.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* | ||
< 91.4.0CPE matchmatch criteria | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | ||
9.0CPE matchmatch criteria | cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | ||
10.0CPE matchmatch criteria | cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.1 Security Researcher mentions.