cel-rust Denial-of-Service Vulnerability in Versions 0.10.0 Prior to 0.11.4

A denial-of-service vulnerability has been identified in the cel-rust Common Expression Language interpreter, present in versions 0.10.0 prior to 0.11.4. The issue arises when the parser processes certain malformed CEL expressions, leading to a panic that terminates the process. This vulnerability can be exploited when the crate evaluates untrusted expressions, such as user-supplied input over an API, allowing an attacker to cause a process crash.

Impact

Exploiting this vulnerability leads to a process panic, causing a crash and interruption of service.

Reproduction

The vulnerability can be reproduced by compiling the cel-rust library version 0.10.0 with the Rust programming language. After compiling, an example can be run that includes a malformed CEL expression, such as 'x(1,'. This input will trigger the parser to panic, demonstrating the denial-of-service condition.

Remediation

Users can upgrade to cel-rust version 0.11.4 to address this vulnerability.