Home/CVE/A use-after-free could have occured when an HTTP2 session object was released on a different thread, leading to memory c
CVE

CVE-2021-43535

A use-after-free could have occured when an HTTP2 session object was released on a different thread, leading to memory c

A use-after-free could have occured when an HTTP2 session object was released on a different thread, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 93, Thunderbird < 91.3, and Firefox ESR < 91.3.

HIGH · CVSS 8.8 EPSS 0.01186
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules1 YARA rules0
⬡

Weakness Classification

CWE-416Use After Free
▤

Affected Products & Versions

4
mozilla firefox< 93.0
mozilla firefox esr< 91.3.0
mozilla thunderbird< 91.3.0
debian linuxall versions
◈

Sigma Hunt Rules

1
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighSQLite Firefox Profile Data DB Access
▣

Scoring & Timeline

8.8
HIGH · CVSS v3.1 · security@mozilla.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD08 Dec 2021 · 10:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
⚑

Vendor Advisories

10
usnUSN-5248-1
rhsaRHSA-2021:4130Critical
rhsaRHSA-2021:4132Critical
rhsaRHSA-2021:4133Critical
rhsaRHSA-2021:4134Critical
🔗

References & Sources

8
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://bugzilla.mozilla.org/show_bug.cgi?id=1667102Issue TrackingPermissions RequiredVendor Advisory
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing ListThird Party Advisory
https://www.debian.org/security/2021/dsa-5026Third Party Advisory
https://www.debian.org/security/2022/dsa-5034Issue TrackingThird Party Advisory
https://www.mozilla.org/security/advisories/mfsa2021-43/Vendor Advisory
Intelligence Graph · click any node to traverse
CVETechnique ActorTool Family
drag to reposition · click any node to traverse · button top-right enlarges
External lookups - second-class, for what we don’t hold ourselves
NVDCVE.orgCISAVulnersExploit-DBGitHub PoCVulnCheck KEVGreyNoise
Vulnerabilities
CISA KEV catalog
CWE weaknesses
CAPEC attack patterns
Package vulnerabilities
Threat intelligence
Threat actors
Tools & malware
ATT&CK techniques
IOCs
Detection & defense
Sigma rules
YARA rules
Atomic Red Team tests
D3FEND countermeasures
Compliance
NIST 800-53
ISO 27001:2022
SOC 2 TSC
PCI-DSS v4.0
CIS Controls v8.1
About
All capabilities
Live statistics
Data sources
Privacy policy
Terms of service
threatengine.sh  ·  Open-source threat intelligence platform  ·  100+ authoritative sources  ·  Every fact traces to its origin