CyberSecBulletin
CVE-2022-38473NVD status: Modified

Thunderbird: Improper Preservation of Permissions

Published Updated By the CyberSecBulletin desk

CVE-2022-38473 is a high-severity improper preservation of permissions vulnerability in Thunderbird from Mozilla, with a CVSS 3.1 base score of 8.8 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 versions 102.2, 91.13 as the first without the flaw, so updating Thunderbird to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.74% chance of exploitation within 30 days, higher than 55% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Thunderbird to 102.2 or 91.13, whichever matches your release line, or a later version.
  2. Update Firefox ESR to 91.13 or 102.2, whichever matches your release line, or a later version.
  3. Update Firefox to 104 or a later version.
  4. Read the advisory on bugzilla.mozilla.org for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  6. 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 102.2; before 91.13102.2, 91.13
MozillaFirefox ESRbefore 91.13; before 102.291.13, 102.2
MozillaFirefoxbefore 104104

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
LowNo special conditions are needed; the attack works reliably.
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:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.8HighNVD
CVSS 3.18.8HighCISA (ADP)

Official description

A cross-origin iframe referencing an XSLT document would inherit the parent domain's permissions (such as microphone or camera access). This vulnerability affects Thunderbird < 102.2, Thunderbird < 91.13, Firefox ESR < 91.13, Firefox ESR < 102.2, and Firefox < 104.

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

The underlying weakness: Improper Preservation of Permissions

The product does not preserve permissions or incorrectly preserves permissions when copying, restoring, or sharing objects, which can cause them to have less restrictive permissions than intended.

More Improper Preservation of Permissions vulnerabilities (CWE-281)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, 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 Improper Preservation of Permissions vulnerabilities

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