BF Taxonomy

DVR (Verify)

Cause: Improper Operation - Missing

Attributes:
Mechanism: Quantity
Source Code: Codebase (d1_both.c and t1_lib.c)
Execution Space: Admin
State: Transferred (via network)

Consequence: Improper Data - Inconsistent Value (size)

Brief Description:

Heartbleed is a vulnerability due to a bug in the OpenSSL that allows a server to read over the bounds of a buffer. Using the heartbeat extension tests in TLS (Transport Layer Security) and DTLS (Datagram Transport Layer Security) protocols, a user can send a heartbeat request to a server. The request contains a string and a payload unsigned integer, which value is expected to be the string size but could be as big as 65535.

Analysis

Fig. 1 presents the BF taxonomy for the Heartbeat DVR bug.

The Fix

To fix the bug, the OpenSSL team added a value verification for the array size.