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TI-2023-04221 Aliases CVE-2023-4577GHSA-fm7w-6qfv-w35j

Memory corruption in JIT UpdateRegExpStatics

Priority LOW 30Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 17 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

When `UpdateRegExpStatics` attempted to access `initialStringHeap` it could already have been garbage collected prior to entering the function, which could potentially have led to an exploitable crash. This vulnerability affects Firefox < 117, Firefox ESR < 115.2, and Thunderbird < 115.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00652 51st percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 117Firefox ESR (Mozilla): 115.2+1 more productRed Hat: 15 advisoriesRed Hat: 17 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefoxbefore 117117Patch availableCNA
MozillaFirefox ESRbefore 115.2115.2Patch availableCNA
MozillaThunderbirdbefore 115.2115.2Patch availableCNA
  • Firefox VendorMozilla Affected before 117 Fixed in 117 Patch available CNA
  • Firefox ESR VendorMozilla Affected before 115.2 Fixed in 115.2 Patch available CNA
  • Thunderbird VendorMozilla Affected before 115.2 Fixed in 115.2 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 117.0VulnerableMozilla
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*before 115.2VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*before 115.2VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 117.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* Versions before 115.2 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 115.2 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 117
  • Fix · CNA Firefox ESR (Mozilla) Fixed in 115.2
  • Fix · CNA Thunderbird (Mozilla) Fixed in 115.2

Red Hat 15 advisories

  • RHSA-2023:5019 Released 2023-09-07 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux Client (v. 7) firefox-102.15.0-1.el7_9
    • Red Hat Enterprise Linux Client Optional (v. 7) firefox-102.15.0-1.el7_9
    • Red Hat Enterprise Linux Server (v. 7) firefox-102.15.0-1.el7_9
    • Red Hat Enterprise Linux Server Optional (v. 7) firefox-102.15.0-1.el7_9
    • Red Hat Enterprise Linux Workstation (v. 7) firefox-102.15.0-1.el7_9
    • Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-102.15.0-1.el7_9
  • RHSA-2023:4954 Released 2023-09-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 8) thunderbird-102.15.0-1.el8_8
  • RHSA-2023:4952 Released 2023-09-04 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 8) firefox-102.15.0-1.el8_8
Show 12 more Red Hat advisories
  • RHSA-2023:4959 Released 2023-09-04 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.8.6) firefox-102.15.0-1.el8_6
  • RHSA-2023:4956 Released 2023-09-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird-102.15.0-1.el8_4
    • Red Hat Enterprise Linux AppStream E4S (v.8.4) thunderbird-102.15.0-1.el8_4
    • Red Hat Enterprise Linux AppStream TUS (v.8.4) thunderbird-102.15.0-1.el8_4
  • RHSA-2023:4957 Released 2023-09-04 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-102.15.0-1.el8_4
    • Red Hat Enterprise Linux AppStream E4S (v.8.4) firefox-102.15.0-1.el8_4
    • Red Hat Enterprise Linux AppStream TUS (v.8.4) firefox-102.15.0-1.el8_4
  • RHSA-2023:4958 Released 2023-09-04 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 9) firefox-102.15.0-1.el9_2, firefox-x11-102.15.0-1.el9_2
  • RHSA-2023:4955 Released 2023-09-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 9) thunderbird-102.15.0-1.el9_2
  • RHSA-2023:4945 Released 2023-09-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux Client (v. 7) thunderbird-102.15.0-1.el7_9
    • Red Hat Enterprise Linux Server Optional (v. 7) thunderbird-102.15.0-1.el7_9
    • Red Hat Enterprise Linux Workstation (v. 7) thunderbird-102.15.0-1.el7_9
  • RHSA-2023:4949 Released 2023-09-04 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v. 8.1) firefox-102.15.0-1.el8_1
  • RHSA-2023:4948 Released 2023-09-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v. 8.1) thunderbird-102.15.0-1.el8_1
  • RHSA-2023:4946 Released 2023-09-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v. 8.2) thunderbird-102.15.0-1.el8_2
    • Red Hat Enterprise Linux AppStream E4S (v. 8.2) thunderbird-102.15.0-1.el8_2
    • Red Hat Enterprise Linux AppStream TUS (v. 8.2) thunderbird-102.15.0-1.el8_2
  • RHSA-2023:4951 Released 2023-09-04 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v. 8.2) firefox-102.15.0-1.el8_2
    • Red Hat Enterprise Linux AppStream E4S (v. 8.2) firefox-102.15.0-1.el8_2
    • Red Hat Enterprise Linux AppStream TUS (v. 8.2) firefox-102.15.0-1.el8_2
  • RHSA-2023:4947 Released 2023-09-04 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.0) thunderbird-102.15.0-1.el9_0
  • RHSA-2023:4950 Released 2023-09-04 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.0) firefox-102.15.0-1.el9_0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Mozilla Firefox 117

    13 records Highest priority Priority MEDIUM 5 MEDIUM, 8 LOW

    Other records, highest priority first

    • TI-2023-04220 Integer Overflow in RecordedSourceSurfaceCreationPriority MEDIUM 45
    • TI-2023-04226 Buffer Overflow in WebGL glGetProgramivPriority MEDIUM 42
    • TI-2023-04229 Memory safety bugs fixed in Firefox 117, Firefox ESR 115.2, and Thunderbird 115.2Priority MEDIUM 41
    Show all 13 records →
  • Release ·

    Mozilla Firefox ESR, Thunderbird 115.2

    12 records Highest priority Priority MEDIUM 5 MEDIUM, 7 LOW

    Other records, highest priority first

    • TI-2023-04220 Integer Overflow in RecordedSourceSurfaceCreationPriority MEDIUM 45
    • TI-2023-04226 Buffer Overflow in WebGL glGetProgramivPriority MEDIUM 42
    • TI-2023-04229 Memory safety bugs fixed in Firefox 117, Firefox ESR 115.2, and Thunderbird 115.2Priority MEDIUM 41
    Show all 12 records →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2023:4952, RHSA-2023:4954
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2023:4955, RHSA-2023:4958
Red Hat Enterprise Linux AppStream AUS (v. 8.2)Fixed RHSA-2023:4946, RHSA-2023:4951
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2023:4956, RHSA-2023:4957
Red Hat Enterprise Linux AppStream E4S (v. 8.1)Fixed RHSA-2023:4948, RHSA-2023:4949
Red Hat Enterprise Linux AppStream E4S (v. 8.2)Fixed RHSA-2023:4946, RHSA-2023:4951
Red Hat Enterprise Linux AppStream E4S (v.8.4)Fixed RHSA-2023:4956, RHSA-2023:4957
Red Hat Enterprise Linux AppStream EUS (v.8.6)Fixed RHSA-2023:4959
Red Hat Enterprise Linux AppStream EUS (v.9.0)Fixed RHSA-2023:4947, RHSA-2023:4950
Red Hat Enterprise Linux AppStream TUS (v. 8.2)Fixed RHSA-2023:4946, RHSA-2023:4951
Red Hat Enterprise Linux AppStream TUS (v.8.4)Fixed RHSA-2023:4956, RHSA-2023:4957
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2023:4945, RHSA-2023:5019
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2023:5019
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2023:5019
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2023:4945, RHSA-2023:5019
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2023:4945, RHSA-2023:5019
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2023:5019

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-4577
  2. 2026-10-03 Alias added: GHSA-fm7w-6qfv-w35j
  3. 2026-10-14 EPSS moved to the 50th–90th percentile

References

Advisory 3

Other 1

  • TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
  • TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
  • TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
  • TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
See all 3444 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences