CVE-2022-1834
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedWhen displaying the sender of an email, and the sender name contained the Braille Pattern Blank space character multiple times, Thunderbird would have displayed all the spaces. This could have been used by an attacker to send an email message with the attacker's digital signature, that was shown with an arbitrary sender email address chosen by the attacker. If the sender name started with a false email address, followed by many Braille space characters, the attacker's email address was not visible. Because Thunderbird compared the invisible sender address with the signature's email address, if the signing key or certificate was accepted by Thunderbird, the email was shown as having a valid digital signature. This vulnerability affects Thunderbird < 91.10.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThunderbird failed to properly render Braille Pattern Blank space characters in email sender display names, allowing attackers to hide the true sender email address by padding with invisible spaces. The email client then incorrectly validated digital signatures by comparing the invisible (hidden) sender address against the signing certificate, rather than the displayed address, causing malicious emails to appear as having valid digital signatures.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 91.10CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check Thunderbird versionOpen Thunderbird, go to Help > About Thunderbird, or run 'thunderbird --version' from command lineAffected if Version is below 91.10 (e.g., 91.9.x or earlier)
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Verify S/MIME or PGP configurationGo to Thunderbird Account Settings and examine the security settings for each configured email account. Check if any accounts have digital signing or encryption enabled.Affected if Digital signature verification (S/MIME or PGP) is enabled for any email account, and Thunderbird version is below 91.10
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Inspect email headers for unusual charactersView the raw source of received emails (View > Message Source) and examine the From header line for unexpected Unicode characters, particularly Braille Pattern Blank (U+2800) or similar whitespace characters preceding or within the display nameAffected if The From header contains display names with hidden/invisible Unicode whitespace characters, and the email shows a valid digital signature despite the spoofed display name
Your environment is affected if Thunderbird version is below 91.10 and you use digital signature verification (S/MIME or PGP) to validate incoming emails.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped91.10
Upgrade Thunderbird to version 91.10 or later, which properly handles Braille space characters in sender display names and correctly associates displayed sender information with signature verification.
Thunderbird 91.10 or later
- Check current Thunderbird version by navigating to Help > About Thunderbird or running 'thunderbird --version' in command line
- Download Thunderbird 91.10 or later from the official Mozilla Thunderbird website (www.thunderbird.net)
- Close Thunderbird completely if running
- Install the downloaded Thunderbird 91.10+ package using your operating system's standard installation method
- Restart Thunderbird and verify the version shows 91.10 or higher
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-1834 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2022-1834 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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