CVE-2025-24904: libsignal-service-rs doesn't sanity check plaintext envelopes are not sanity-checked
Description
libsignal-service-rs is a Rust version of the libsignal-service-java library which implements the core functionality to communicate with Signal servers. Prior to commit 82d70f6720e762898f34ae76b0894b0297d9b2f8, plaintext content envelopes could be injected by a server or a malicious client, and may have been able to bypass the end-to-end encryption and authentication. The vulnerability is fixed per 82d70f6720e762898f34ae76b0894b0297d9b2f8. The `Metadata` struct contains an additional `was_encrypted` field, which breaks the API, but should be easily resolvable. No known workarounds are available.
Classification
CVE ID: CVE-2025-24904
CVSS Base Severity: HIGH
CVSS Base Score: 8.5
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N
Affected Products
Vendor: whisperfish
Product: libsignal-service-rs
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.04% (probability of being exploited)
EPSS Percentile: 11.98% (scored less or equal to compared to others)
EPSS Date: 2025-03-14 (when was this score calculated)
References
https://github.com/whisperfish/libsignal-service-rs/security/advisories/GHSA-hrrc-wpfw-5hj2https://github.com/whisperfish/libsignal-service-rs/commit/82d70f6720e762898f34ae76b0894b0297d9b2f8