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.
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
Red Hat Enterprise 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.
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