CVE-2024-1546 – This vulnerability allows attackers to read mem... (How to Fix)

Q: How do I fix CVE-2024-1546?

1. Open Firefox/Thunderbird. 2. Click menu → Help → About Firefox/Thunderbird. 3. Allow automatic update download and installation. 4. Restart the application when prompted.

Q: What is the severity of CVE-2024-1546?

CVE-2024-1546 has a CVSS score of 7.5 (HIGH). This vulnerability allows attackers to read memory outside the intended buffer boundaries when Firefox, Firefox ESR, or Thunderbird processes network data. It affects all users running vulnerable versions of these applications. Successful exploitation could leak sensitive information from browser memory.

📋 TL;DR

This vulnerability allows attackers to read memory outside the intended buffer boundaries when Firefox, Firefox ESR, or Thunderbird processes network data. It affects all users running vulnerable versions of these applications. Successful exploitation could leak sensitive information from browser memory.

💻 Affected Systems

Products:

Firefox
Firefox ESR
Thunderbird

Versions: Firefox < 123, Firefox ESR < 115.8, Thunderbird < 115.8

Operating Systems: Windows, Linux, macOS

Default Config Vulnerable: ⚠️ Yes

Notes: All default configurations are vulnerable. No special configuration required for exploitation.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Information disclosure leading to exposure of sensitive data like passwords, session tokens, or other memory contents to attackers.

🟠

Likely Case

Memory content leakage that could be combined with other vulnerabilities for more severe attacks, or direct exposure of user data.

🟢

If Mitigated

Limited impact with proper network segmentation and updated software, though information disclosure risk remains if exploited.

🌐 Internet-Facing: HIGH - These applications directly process untrusted internet content and network data.

🏢 Internal Only: MEDIUM - Internal use still involves processing potentially malicious content from emails or internal web applications.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires tricking users into visiting malicious websites or opening malicious emails. No authentication required for the memory read.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Firefox 123+, Firefox ESR 115.8+, Thunderbird 115.8+

Vendor Advisory: https://www.mozilla.org/security/advisories/mfsa2024-05/

Restart Required: Yes

Instructions:

1. Open Firefox/Thunderbird. 2. Click menu → Help → About Firefox/Thunderbird. 3. Allow automatic update download and installation. 4. Restart the application when prompted.

🔧 Temporary Workarounds

Disable JavaScript

all

Prevents many web-based exploitation vectors but severely limits functionality

about:config → javascript.enabled = false

Network Segmentation

all

Restrict browser access to sensitive internal networks

🧯 If You Can't Patch

Isolate affected systems from sensitive networks and data
Implement application whitelisting to prevent execution of malicious content

🔍 How to Verify

Check if Vulnerable:

Check application version in Help → About Firefox/Thunderbird

Check Version:

firefox --version or thunderbird --version

Verify Fix Applied:

Confirm version is Firefox ≥123, Firefox ESR ≥115.8, or Thunderbird ≥115.8

📡 Detection & Monitoring

Log Indicators:

Application crashes with memory access violations
Unusual outbound data transfers from browser processes

Network Indicators:

Suspicious connections to known malicious domains combined with browser crashes

SIEM Query:

source="*firefox*" OR source="*thunderbird*" AND (event_type="crash" OR memory_access_violation)

📊 Metadata

CVE ID: CVE-2024-1546

CVSS v3 Score: 7.5 (HIGH)

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

CWE: CWE-125

Published: February 20, 2024

Last Updated: March 27, 2025

🔗 References

https://bugzilla.mozilla.org/show_bug.cgi?id=1843752 Issue Tracking
https://lists.debian.org/debian-lts-announce/2024/03/msg00000.html Mailing List
https://lists.debian.org/debian-lts-announce/2024/03/msg00001.html Mailing List
https://www.mozilla.org/security/advisories/mfsa2024-05/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2024-06/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2024-07/ Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1843752 Issue Tracking
https://lists.debian.org/debian-lts-announce/2024/03/msg00000.html Mailing List
https://lists.debian.org/debian-lts-announce/2024/03/msg00001.html Mailing List
https://www.mozilla.org/security/advisories/mfsa2024-05/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2024-06/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2024-07/ Vendor Advisory

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🔗 Related Vulnerabilities

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