Fixed
Created: Feb 28, 2016
Updated: Sep 8, 2018
Resolved Date: Mar 1, 2016
Found In Version: 7.0
Fix Version: 7.0.0.16
Severity: Critical
Applicable for: Wind River Linux 7
Component/s: Userspace
Note: This issue is corrected by the CVE-2015-0293 patch. No further patch will be issued for this CVE.
Divide-and-conquer session key recovery in SSLv2 (CVE-2016-0703)
================================================================
Severity: High
This issue only affected versions of OpenSSL prior to March 19th 2015 at which
time the code was refactored to address vulnerability CVE-2015-0293.
s2_srvr.c did not enforce that clear-key-length is 0 for non-export ciphers. If
clear-key bytes are present for these ciphers, they *displace* encrypted-key
bytes. This leads to an efficient divide-and-conquer key recovery attack: if an
eavesdropper has intercepted an SSLv2 handshake, they can use the server as an
oracle to determine the SSLv2 master-key, using only 16 connections to the
server and negligible computation.
More importantly, this leads to a more efficient version of DROWN that is
effective against non-export ciphersuites, and requires no significant
computation.
This issue affected OpenSSL versions 1.0.2, 1.0.1l, 1.0.0q, 0.9.8ze and all
earlier versions. It was fixed in OpenSSL 1.0.2a, 1.0.1m, 1.0.0r and 0.9.8zf
(released March 19th 2015).
This issue was reported to OpenSSL on February 10th 2016 by David Adrian and J.
Alex Halderman of the University of Michigan. The underlying defect had by
then already been fixed by Emilia Käsper of OpenSSL on March 4th 2015. The fix
for this issue can be identified by commits ae50d827 (1.0.2a), cd56a08d
(1.0.1m), 1a08063 (1.0.0r) and 65c588c (0.9.8zf).
