Thunderbird: Improper Neutralization of Input During Web Page Generation
CVE-2022-3033 is a high-severity improper neutralization of input during web page generation vulnerability in Thunderbird from Mozilla, with a CVSS 3.1 base score of 8.1 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 102.2.1, 91.13.1 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 0.8% chance of exploitation within 30 days, higher than 57% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Thunderbird to 102.2.1 or 91.13.1, whichever matches your release line, or a later version.
- Read the advisory on bugzilla.mozilla.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Mozilla | Thunderbird | before 102.2.1; before 91.13.1 | 102.2.1, 91.13.1 |
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
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.1 | High | NVD |
| CVSS 3.1 | 8.1 | High | CISA (ADP) |
Official description
If a Thunderbird user replied to a crafted HTML email containing a <code>meta</code> tag, with the <code>meta</code> tag having the <code>http-equiv="refresh"</code> attribute, and the content attribute specifying an URL, then Thunderbird started a network request to that URL, regardless of the configuration to block remote content. In combination with certain other HTML elements and attributes in the email, it was possible to execute JavaScript code included in the message in the context of the message compose document. The JavaScript code was able to perform actions including, but probably not limited to, read and modify the contents of the message compose document, including the quoted original message, which could potentially contain the decrypted plaintext of encrypted data in the crafted email. The contents could then be transmitted to the network, either to the URL specified in the META refresh tag, or to a different URL, as the JavaScript code could modify the URL specified in the document. This bug doesn't affect users who have changed the default Message Body display setting to 'simple html' or 'plain text'. This vulnerability affects Thunderbird < 102.2.1 and Thunderbird < 91.13.1.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Input During Web Page Generation
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
How developers prevent this class of flaw
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
- Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Input During Web Page Generation vulnerabilities (CWE-79)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- bugzilla.mozilla.org/show_bug.cgi?id=1784838Issue Tracking, Permissions Required
- mozilla.org/security/advisories/mfsa2022-38/
- mozilla.org/security/advisories/mfsa2022-39/
Other vulnerabilities in Thunderbird
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
Recent Improper Neutralization of Input During Web Page Generation vulnerabilities
- 9.0 Critical severity
- 8.4 High severity
- 9.6 Critical severity
- 9.6 Critical severity
- 8.8 High severity
- 8.8 High severity
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