nCipher PKCS#11 library C_Verify performs improper validation of symmetric signatures

ncipher-cverify-improper-verification (9895) The risk level is classified as MediumMedium Risk


The nCipher PKCS#11 library improperly validates symmetric signatures, which is caused by a vulnerability in the error-checking routine in the C_Verify call. This vulnerability causes invalid symmetric signatures to be always treated as valid, which could allow remote attackers to use invalid signatures on messages that are validated using the nCipher PKCS#11 library.


Bypass Security


nCipher customers should contact nCipher support for upgrade or patch information. See References.


  • BugTraq Mailing List, Mon Aug 19 2002 - 11:20:29 CDT: nCipher Advisory #5: C_Verify validates incorrect symmetric signatures.
  • nCipher Security Advisory No. 5: C_Verify validates incorrect symmetric signatures.
  • BID-5498: nCipher PKCS#11 Symmetric Message Signature Verification Vulnerability
  • CVE-2002-1446: The error checking routine used for the C_Verify call on a symmetric verification key in the nCipher PKCS#11 library 1.2.0 and later returns the CKR_OK status even when it detects an invalid signature, which could allow remote attackers to modify or forge messages.
  • OSVDB ID: 14876: nCipher PKCS#11 Library C_Verify Call Error Routine Failure

Platforms Affected:

  • nCipher nCipher PKCS#11 library 1.2.0


Aug 19, 2002

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