CVE-2024-32986

PWAsForFirefox is a tool to install, manage and use Progressive Web Apps (PWAs) in Mozilla Firefox. Due to improper sanitization of web app properties (such as name, description, shortcuts), web apps were able to inject additional lines into XDG Desktop Entries (on Linux) and AppInfo.ini (on PortableApps.com). This allowed malicious web apps to introduce keys like Exec, which could run arbitrary code when the affected web app was launched. This vulnerability affects all Linux and PortableApps.com users of all PWAsForFirefox versions up to (excluding) 2.12.0. Windows and macOS users are not affected. This vulnerability has been fixed in commit 9932d4b which has been included in release in v2.12.0. The main fix is implemented in the native part, but the extension also contains additional fixes. All Linux and PortableApps.com users are advised to update to this version as soon as possible. It is also recommended for Windows and macOS users to update to this version, as it contains additional fixes related to properties sanitization. There are no known workarounds for this vulnerability.

Weakness

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component.

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/134.html
• https://cwe.mitre.org/data/definitions/41.html
• https://cwe.mitre.org/data/definitions/81.html
• https://cwe.mitre.org/data/definitions/93.html

References

• https://github.com/filips123/PWAsForFirefox/commit/9932d4b289631d447f88ace09a2fabafe4cd5bd5
• https://github.com/filips123/PWAsForFirefox/releases/tag/v2.12.0
• https://github.com/filips123/PWAsForFirefox/security/advisories/GHSA-jmhv-m7v5-g5jq