CVE-2018-18501

Q: How do I fix CVE-2018-18501?

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

Q: What is the severity of CVE-2018-18501?

CVE-2018-18501 has a CVSS score of 9.8 (CRITICAL). This CVE describes memory safety bugs in Mozilla Firefox and Thunderbird that could lead to memory corruption. With sufficient effort, attackers could exploit these vulnerabilities to execute arbitrary code on affected systems. The vulnerability impacts Thunderbird versions below 60.5, Firefox ESR below 60.5, and Firefox below 65.

9.8 CRITICAL

Remote Code Execution

📋 TL;DR

This CVE describes memory safety bugs in Mozilla Firefox and Thunderbird that could lead to memory corruption. With sufficient effort, attackers could exploit these vulnerabilities to execute arbitrary code on affected systems. The vulnerability impacts Thunderbird versions below 60.5, Firefox ESR below 60.5, and Firefox below 65.

💻 Affected Systems

Products:

Mozilla Firefox
Mozilla Firefox ESR
Mozilla Thunderbird

Versions: Thunderbird < 60.5, Firefox ESR < 60.5, Firefox < 65

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

Remote code execution leading to complete system compromise, data theft, or ransomware deployment

🟠

Likely Case

Browser/email client crash or instability, with potential for limited code execution in targeted attacks

🟢

If Mitigated

Denial of service through application crashes if memory corruption occurs but code execution fails

🌐 Internet-Facing: HIGH - Web browsers and email clients frequently process untrusted content from the internet

🏢 Internal Only: MEDIUM - Internal web applications and email could still be attack vectors

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: HIGH

Memory corruption vulnerabilities require sophisticated exploitation techniques, but successful exploitation could lead to arbitrary code execution without user authentication.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Thunderbird 60.5, Firefox ESR 60.5, Firefox 65

Vendor Advisory: https://www.mozilla.org/en-US/security/advisories/mfsa2019-01/

Restart Required: Yes

Instructions:

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

🔧 Temporary Workarounds

Disable JavaScript

all

Temporarily disable JavaScript to reduce attack surface while waiting for patch

about:config → javascript.enabled = false

Use Content Security Policy

all

Implement strict CSP headers on web servers to limit script execution

Content-Security-Policy: default-src 'self'

🧯 If You Can't Patch

Isolate affected systems from untrusted networks and internet access
Implement application whitelisting to prevent execution of unauthorized code

🔍 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 Thunderbird ≥ 60.5, Firefox ESR ≥ 60.5, or Firefox ≥ 65

📡 Detection & Monitoring

Log Indicators:

Application crash logs with memory access violations
Unexpected process termination

Network Indicators:

Unusual outbound connections from browser/email client
Suspicious JavaScript payloads in web traffic

SIEM Query:

source="*firefox.log" OR source="*thunderbird.log" AND ("crash" OR "segmentation fault" OR "access violation")

📊 Metadata

CVE ID: CVE-2018-18501

CVSS v3 Score: 9.8 (CRITICAL)

CVSS Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-119

Published: February 5, 2019

Last Updated: November 21, 2024

🔗 References

http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00021.html
http://www.securityfocus.com/bid/106781 Third Party Advisory,VDB Entry
https://access.redhat.com/errata/RHSA-2019:0218 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0219 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0269 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0270 Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/01/msg00025.html Mailing List,Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/02/msg00024.html Mailing List,Third Party Advisory
https://security.gentoo.org/glsa/201903-04 Third Party Advisory
https://security.gentoo.org/glsa/201904-07
https://usn.ubuntu.com/3874-1/ Third Party Advisory
https://usn.ubuntu.com/3897-1/ Third Party Advisory
https://www.debian.org/security/2019/dsa-4376 Third Party Advisory
https://www.debian.org/security/2019/dsa-4392 Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2019-01/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-02/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-03/ Vendor Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00021.html
http://www.securityfocus.com/bid/106781 Third Party Advisory,VDB Entry
https://access.redhat.com/errata/RHSA-2019:0218 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0219 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0269 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0270 Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/01/msg00025.html Mailing List,Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/02/msg00024.html Mailing List,Third Party Advisory
https://security.gentoo.org/glsa/201903-04 Third Party Advisory
https://security.gentoo.org/glsa/201904-07
https://usn.ubuntu.com/3874-1/ Third Party Advisory
https://usn.ubuntu.com/3897-1/ Third Party Advisory
https://www.debian.org/security/2019/dsa-4376 Third Party Advisory
https://www.debian.org/security/2019/dsa-4392 Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2019-01/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-02/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-03/ Vendor Advisory

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Debian Linux by Debian

Debian Linux by Debian

Enterprise Linux Desktop by Redhat

Enterprise Linux Desktop by Redhat

Enterprise Linux Server by Redhat

Enterprise Linux Server by Redhat

Enterprise Linux Server Aus by Redhat

Enterprise Linux Server Eus by Redhat

Enterprise Linux Workstation by Redhat

Enterprise Linux Workstation by Redhat

Firefox by Mozilla

Firefox Esr by Mozilla

Thunderbird by Mozilla

Ubuntu Linux by Canonical

Ubuntu Linux by Canonical

Ubuntu Linux by Canonical

Ubuntu Linux by Canonical

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Disable JavaScript

Use Content Security Policy

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

🔗 Related Vulnerabilities