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Sid 1-38575

Message

SERVER-OTHER OpenSSL TLS change cipher spec protocol denial of service attempt

Summary

This event is generated when an OpenSSL TLS change cipher spec denial of service is detected.

Impact

Attempted Denial of Service

CVE-2013-6449:

CVSS base score 4.3

CVSS impact score 2.9

CVSS exploitability score 8.6

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact PARTIAL

Detailed information

CVE-2013-6449: The sslgetalgorithm2 function in ssl/s3_lib.c in OpenSSL before 1.0.2 obtains a certain version number from an incorrect data structure, which allows remote attackers to cause a denial of service (daemon crash) via crafted traffic from a TLS 1.2 client.

Affected systems

  • openssl openssl 1.0.0
  • openssl openssl 1.0.0a
  • openssl openssl 1.0.0b
  • openssl openssl 1.0.0c
  • openssl openssl 1.0.0d
  • openssl openssl 1.0.0e
  • openssl openssl 1.0.0f
  • openssl openssl 1.0.0g
  • openssl openssl 1.0.0h
  • openssl openssl 1.0.0i
  • openssl openssl 1.0.0j
  • openssl openssl 1.0.1
  • openssl openssl 1.0.1a
  • openssl openssl 1.0.1b
  • openssl openssl 1.0.1c
  • openssl openssl 1.0.1d
  • openssl openssl 1.0.1e

Ease of attack

CVE-2013-6449:

Access Vector NETWORK

Access Complexity MEDIUM

Authentication NONE

False positives

None Known

False negatives

None Known

Corrective action

Contributors

  • Cisco's Talos Intelligence Group

Additional References

  • www.openssl.org/news/vulnerabilities.html#2013-6449