CyberSecBulletin
CVE-2022-24884NVD status: Modified

ecdsautils: Improper Verification of Cryptographic Signature

Published Updated By the CyberSecBulletin desk

CVE-2022-24884 is a high-severity improper verification of cryptographic signature vulnerability in ecdsautils from Freifunk-gluon, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected ecdsautils versions: < 0.4.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.04% chance of exploitation within 30 days, higher than 65% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of ecdsautils 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.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Freifunk-gluonecdsautils< 0.4.1Not stated
Fedora ProjectFedora34; 35; 36Not stated
DebianDebian Linux9.0; 10.0; 11.0Not 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
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.110.0CriticalCNA (github.com)
CVSS 3.17.5HighNVD
CVSS 2.05.0MediumNVD

Official description

ecdsautils is a tiny collection of programs used for ECDSA (keygen, sign, verify). `ecdsa_verify_[prepare_]legacy()` does not check whether the signature values `r` and `s` are non-zero. A signature consisting only of zeroes is always considered valid, making it trivial to forge signatures. Requiring multiple signatures from different public keys does not mitigate the issue: `ecdsa_verify_list_legacy()` will accept an arbitrary number of such forged signatures. Both the `ecdsautil verify` CLI command and the libecdsautil library are affected. The issue has been fixed in ecdsautils 0.4.1. All older versions of ecdsautils (including versions before the split into a library and a CLI utility) are vulnerable.

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

The underlying weakness: Improper Verification of Cryptographic Signature

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

More Improper Verification of Cryptographic Signature vulnerabilities (CWE-347)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Recent Improper Verification of Cryptographic Signature vulnerabilities

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