CVE-2023-30844

Mutagen provides real-time file synchronization and flexible network forwarding for developers. Prior to versions 0.16.6 and 0.17.1 in mutagen and prior to version 0.17.1 in mutagen-compose, Mutagen list and monitor commands are susceptible to control characters that could be provided by remote endpoints. This could cause terminal corruption, either intentional or unintentional, if these characters were present in error messages or file paths/names. This could be used as an attack vector if synchronizing with an untrusted remote endpoint, synchronizing files not under control of the user, or forwarding to/from an untrusted remote endpoint. On very old systems with terminals susceptible to issues such as CVE-2003-0069, the issue could theoretically cause code execution. The problem has been patched in Mutagen v0.16.6 and v0.17.1. Earlier versions of Mutagen are no longer supported and will not be patched. Versions of Mutagen after v0.18.0 will also have the patch merged. As a workaround, avoiding synchronization of untrusted files or interaction with untrusted remote endpoints should mitigate any risk.

Weakness

The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.

Affected Software

Extended Description

Improper encoding or escaping can allow attackers to change the commands that are sent to another component, inserting malicious commands instead. Most products follow a certain protocol that uses structured messages for communication between components, such as queries or commands. These structured messages can contain raw data interspersed with metadata or control information. For example, “GET /index.html HTTP/1.1” is a structured message containing a command (“GET”) with a single argument ("/index.html") and metadata about which protocol version is being used (“HTTP/1.1”). If an application uses attacker-supplied inputs to construct a structured message without properly encoding or escaping, then the attacker could insert special characters that will cause the data to be interpreted as control information or metadata. Consequently, the component that receives the output will perform the wrong operations, or otherwise interpret the data incorrectly.

Potential Mitigations

• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.
• Alternately, use built-in functions, but consider using wrappers in case those functions are discovered to have a vulnerability.
• If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
• For example, stored procedures can enforce database query structure and reduce the likelihood of SQL injection.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/104.html
• https://cwe.mitre.org/data/definitions/73.html
• https://cwe.mitre.org/data/definitions/81.html
• https://cwe.mitre.org/data/definitions/85.html

References

• https://github.com/mutagen-io/mutagen/releases/tag/v0.16.6
• https://github.com/mutagen-io/mutagen/releases/tag/v0.17.1
• https://github.com/mutagen-io/mutagen/security/advisories/GHSA-jmp2-wc4p-wfh2