Cyber Resilience

CVE-2024-9398

Mozilla Thunderbird ≤ 128.3

Published
01 October 2024
Modified
18 March 2025
Patch / advisory
View advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0056 44th percentile
Risk Priority 46 floored blend · peak EPSS

Summary

CVE-2024-9398 is a medium-severity Observable Discrepancy (CWE-203) vulnerability in Mozilla Thunderbird. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Account Discovery (T1087); ranked at the 44th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to IA-6 (Authentication Feedback) and SI-11 (Error Handling) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

By checking the result of calls to `window.open` with specifically set protocol handlers, an attacker could determine if the application which implements that protocol handler is installed. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3,…

more

and Thunderbird < 131.

CWE(s)
NVD-CWE-noinfoCWE-203

Related Threats

MITRE ATT&CK Enterprise Techniques

T1087 Account Discovery Discovery
Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment.
attack.mitre.org →
T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
T1595 Active Scanning Reconnaissance
Adversaries may execute active reconnaissance scans to gather information that can be used during targeting.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-25728Same product: Mozilla Firefox
CVE-2024-10463Same product: Mozilla Firefox
CVE-2024-5690Same product: Mozilla Firefox
CVE-2023-5722Same product: Mozilla Firefox
CVE-2024-5697Same product: Mozilla Firefox
CVE-2023-25741Same product: Mozilla Firefox
CVE-2023-6135Same product: Mozilla Firefox
CVE-2023-5388Same product: Mozilla Firefox
CVE-2023-25742Same product: Mozilla Firefox
CVE-2023-4421Same vendor: Mozilla

Affected Assets

mozilla
firefox
≤ 131.0
mozilla
firefox esr
≤ 128.3.0
mozilla
thunderbird
129.0 · ≤ 128.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 1 hardening rule · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

IA-6 Authentication Feedback good match

Obscures authentication feedback so that success/failure differences are not observable to attackers.

SI-11 Error Handling good match

Requires error messages to avoid revealing exploitable details, directly stopping observable response discrepancies.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent observable response discrepancies via consistent error handling and timing.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.17 Clock synchronization none match
none

Accurate, synchronized timestamps reduce observable timing discrepancies that an attacker could exploit to infer sensitive information or distinguish between success and failure paths.

References