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Improper Verification of Cryptographic Signature

CVE-2018-16150

Medium
5.9/10

Summary

In sig_verify() in x509.c in axTLS version 2.1.3 and before, the PKCS#1 v1.5 signature verification does not reject excess data after the hash value. Consequently, a remote attacker can forge signatures when small public exponents are being used, which could lead to impersonation through fake X.509 certificates. This is a variant of CVE-2006-4340.

  • HIGH
  • NETWORK
  • HIGH
  • UNCHANGED
  • NONE
  • NONE
  • NONE
  • NONE

CWE-347 - Improper Verification of Cryptographic Signature

A cryptographic protocol is meant to ensure that services are provided in a secure manner. An application with absent or improper verification of cryptographic signatures allows malicious users to feed false messages to valid users or to disclose sensitive data, subverting the goals of the protocol. This can lead to security failures such as false authentication, account hijacking, and privilege escalation.

References

Advisory Timeline

  • Published