Family: Red Hat Local Security Checks --> Category: infos
RHSA-2003-102: openssl Vulnerability Scan
Vulnerability Scan Summary
Check for the version of the openssl packages
Detailed Explanation for this Vulnerability Test
Updated OpenSSL packages are available that fix a potential timing-based
attack and a modified Bleichenbacher attack.
[Updated 30 May 2003]
Added missing i686 packages.
OpenSSL is a commercial-grade, full-featured, open source toolkit that
implements the Secure Sockets Layer (SSL v2/v3) and Transport Layer
Security (TLS v1) protocols, and provides a full-strength general purpose
Researchers discovered a timing attack on RSA keys. Applications making
use of OpenSSL are generally vulnerable to such an attack, unless RSA
blinding has been turned on. OpenSSL does not use RSA blinding by default
and most applications do not enable RSA blinding.
A local or remote attacker could use this attack to obtain the server's
private key by determining factors using timing differences on (1) the
number of extra reductions during Montgomery reduction, and (2) the use of
different integer multiplication algorithms (Karatsuba and normal).
In order for an attack to be sucessful, a possible hacker must have good
network conditions that allow small changes in timing to be reliably
Additionally, the SSL and TLS components for OpenSSL allow remote attackers
to perform an unauthorized RSA private key operation via a modified
Bleichenbacher attack. This attack (also known as the Klima-Pokorny-Rosa
attack) uses a large number of SSL or TLS connections using PKCS #1 v1.5
padding to cause OpenSSL to leak information regarding the relationship
between ciphertext and the associated plaintext.
These erratum packages contain a patch provided by the OpenSSL group that
enables RSA blinding by default, and protects against the
Because server applications are affected by these vulnerabilities, we
advise users to restart all services that use OpenSSL functionality or,
alternatively, reboot their systems after installing these updates.
Solution : http://rhn.redhat.com/errata/RHSA-2003-102.html
Threat Level: High
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