CyberSecBulletin
CVE-2025-24903NVD status: Deferred

libsignal-service-rs: Insufficient Verification of Data Authenticity

CVE-2025-24903 is a high-severity insufficient verification of data authenticity vulnerability in libsignal-service-rs from Whisperfish, with a CVSS 3.1 base score of 8.5 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected libsignal-service-rs versions: < 82d70f6720e762898f34ae76b0894b0297d9b2f8. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.19% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of libsignal-service-rs you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Whisperfishlibsignal-service-rs< 82d70f6720e762898f34ae76b0894b0297d9b2f8Not stated

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
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
LowSome restricted data 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:L/UI:N/S:C/C:L/I:H/A:N. Scored by CNA (github.com).

Official 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, any contact may forge a sync message, impersonating another device of the local user. The origin of sync messages is not checked. Patched libsignal-service can be found after commit 82d70f6720e762898f34ae76b0894b0297d9b2f8. The `Metadata` struct contains an additional `was_encrypted` field, which breaks the API, but should be easily resolvable. No known workarounds are available.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

More Insufficient Verification of Data Authenticity vulnerabilities (CWE-345)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in libsignal-service-rs

All libsignal-service-rs vulnerabilities

Recent Insufficient Verification of Data Authenticity vulnerabilities

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