Vigil@nce: TLS, OpenSSL, GnuTLS: vulnerability of the renegotiation
November 2009 by Vigil@nce
A remote attacker can use a vulnerability of TLS in order to
insert pain text data during a renegotiation via a
man-in-the-middle attack.
– Severity: 2/4
– Consequences: data creation/edition
– Provenance: internet client
– Means of attack: no proof of concept, no attack
– Ability of attacker: expert (4/4)
– Confidence: confirmed by the editor (5/5)
– Diffusion of the vulnerable configuration: high (3/3)
– Creation date: 10/11/2009
IMPACTED PRODUCTS
– Apache httpd
– Debian Linux
– HTTPS
– OpenSSL
– Red Hat Enterprise Linux
– Slackware Linux
– Unix - plateform
DESCRIPTION OF THE VULNERABILITY
Transport Layer Security (TLS) is a cryptographic protocol for
network transport.
When opening a connection using TLS, a negotiation mechanism
allows the client and server to agree on the encryption algorithm
to use.
The protocol allows for renegotiation at any time during the
connection. However, the handling of those renegotiations has a
vulnerability.
A remote attacker can therefore exploit this vulnerability in
order to insert pain text data via a man-in-the-middle attack.
CHARACTERISTICS
– Identifiers: 111046, BID-36935, cisco-sa-20091109-tls, CTX123359,
CVE-2009-3555, DSA-1934-1, RHSA-2009:1579-02, RHSA-2009:1580-02,
SSA:2009-320-01, VIGILANCE-VUL-9181, VU#120541
– Url: http://vigilance.fr/vulnerability/TLS-OpenSSL-GnuTLS-vulnerability-of-the-renegotiation-9181