Vulnerability Name:

CVE-2021-43535 (CCN-214851)

Assigned:2021-11-02
Published:2021-11-02
Updated:2022-03-17
Summary: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.
CVSS v3 Severity:8.8 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
7.7 High (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
6.5 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H)
5.7 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
8.8 High (REDHAT CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
7.7 High (REDHAT Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
CVSS v2 Severity:6.8 Medium (CVSS v2 Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Medium
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): Partial
Availibility (A): Partial
6.8 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:S/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-416
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2021-43535

Source: MISC
Type: Issue Tracking, Permissions Required, Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1667102

Source: XF
Type: UNKNOWN
mozilla-firefox-cve202143535-dos(214851)

Source: MLIST
Type: Mailing List, Third Party Advisory
[debian-lts-announce] 20211229 [SECURITY] [DLA 2863-1] firefox-esr security update

Source: MLIST
Type: Mailing List, Third Party Advisory
[debian-lts-announce] 20220104 [SECURITY] [DLA 2874-1] thunderbird security update

Source: DEBIAN
Type: Third Party Advisory
DSA-5026

Source: DEBIAN
Type: Issue Tracking, Third Party Advisory
DSA-5034

Source: CCN
Type: Mozilla Foundation Security Advisory 2021-43
Mozilla Foundation Security Advisory 2021-43 Security Vulnerabilities fixed in Firefox 93

Source: CCN
Type: Mozilla Foundation Security Advisory 2021-49
Security Vulnerabilities fixed in Firefox ESR 91.3

Source: CCN
Type: Mozilla Foundation Security Advisory 2021-50
Security Vulnerabilities fixed in Thunderbird 91.3

Source: MISC
Type: Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-43/

Source: MISC
Type: Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-49/

Source: MISC
Type: Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-50/

Vulnerable Configuration:Configuration 1:
  • cpe:/a:mozilla:firefox:*:*:*:*:*:*:*:* (Version < 93.0)
  • OR cpe:/a:mozilla:firefox_esr:*:*:*:*:*:*:*:* (Version < 91.3.0)
  • OR cpe:/a:mozilla:thunderbird:*:*:*:*:*:*:*:* (Version < 91.3.0)

    • Configuration 2:
  • cpe:/o:debian:debian_linux:9.0:*:*:*:*:*:*:*
  • OR cpe:/o:debian:debian_linux:10.0:*:*:*:*:*:*:*
  • OR cpe:/o:debian:debian_linux:11.0:*:*:*:*:*:*:*

    • Configuration RedHat 1:
  • cpe:/o:redhat:enterprise_linux:7:*:*:*:*:*:*:*

    • Configuration RedHat 2:
  • cpe:/o:redhat:enterprise_linux:7::client:*:*:*:*:*

    • Configuration RedHat 3:
  • cpe:/o:redhat:enterprise_linux:7::server:*:*:*:*:*

    • Configuration RedHat 4:
  • cpe:/o:redhat:enterprise_linux:7::workstation:*:*:*:*:*

    • Configuration RedHat 5:
  • cpe:/a:redhat:enterprise_linux:8:*:*:*:*:*:*:*

    • Configuration RedHat 6:
  • cpe:/a:redhat:enterprise_linux:8::appstream:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:com.redhat.rhsa:def:20214130
    P
    		RHSA-2021:4130: thunderbird security update (Important)
    2021-11-04
    oval:com.redhat.rhsa:def:20214134
    P
    		RHSA-2021:4134: thunderbird security update (Important)
    2021-11-04
    oval:com.redhat.rhsa:def:20214116
    P
    		RHSA-2021:4116: firefox security update (Important)
    2021-11-03
    oval:com.redhat.rhsa:def:20214123
    P
    		RHSA-2021:4123: firefox security update (Important)
    2021-11-03
    BACK
    mozilla firefox *
    mozilla firefox esr *
    mozilla thunderbird *
    debian debian linux 9.0
    debian debian linux 10.0
    debian debian linux 11.0