CyberSecBulletin
CVE-2024-1936NVD status: Analyzed

Thunderbird: Insecure Storage of Sensitive Information

CVE-2024-1936 is a high-severity insecure storage of sensitive information vulnerability in Thunderbird from Mozilla, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 115.8.1 as the first without the flaw, so updating Thunderbird to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.68% chance of exploitation within 30 days, higher than 53% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Thunderbird to 115.8.1 or a later version.
  2. Read the advisory on bugzilla.mozilla.org for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
MozillaThunderbirdbefore 115.8.1115.8.1
DebianDebian Linux10.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CISA (ADP).

Official description

The encrypted subject of an email message could be incorrectly and permanently assigned to an arbitrary other email message in Thunderbird's local cache. Consequently, when replying to the contaminated email message, the user might accidentally leak the confidential subject to a third-party. While this update fixes the bug and avoids future message contamination, it does not automatically repair existing contaminations. Users are advised to use the repair folder functionality, which is available from the context menu of email folders, which will erase incorrect subject assignments. This vulnerability affects Thunderbird < 115.8.1.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Insecure Storage of Sensitive Information

The product stores sensitive information without properly limiting read or write access by unauthorized actors.

More Insecure Storage of Sensitive Information vulnerabilities (CWE-922)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Thunderbird

All Thunderbird vulnerabilities

Recent Insecure Storage of Sensitive Information vulnerabilities

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