Skip to main content

Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')

CVE-2014-3511

Severity Medium
Score 4.3/10

Summary

The ssl23_get_client_hello function in s23_srvr.c in OpenSSL 1.0.1 before 1.0.1i allows man-in-the-middle attackers to force the use of TLS 1.0 by triggering ClientHello message fragmentation in communication between a client and server that both support later TLS versions, related to a "protocol downgrade" issue.

  • MEDIUM
  • NETWORK
  • NONE
  • PARTIAL
  • NONE
  • NONE

CWE-757 - Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')

A protocol or its implementation supports interaction between multiple actors and allows those actors to negotiate which algorithm should be used as a protection mechanism such as encryption or authentication, but it does not select the strongest algorithm that is available to both parties.

Advisory Timeline

  • Published