Updated OpenSSL packages are available that fix ASN.1 parsing vulnerabilities.
OpenSSL is a commercial-grade, full-featured, and open source toolkit that implements Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography library. NISCC testing of implementations of the SSL protocol uncovered two bugs in OpenSSL 0.9.6. The parsing of unusual ASN.1 tag values can cause OpenSSL to crash. A remote attacker could trigger this bug by sending a carefully crafted SSL client certificate to an application. The effects of such an attack vary depending on the application targetted; against Apache the effects are limited, as the attack would only cause child processes to die and be replaced. An attack against other applications that use OpenSSL could result in a Denial of Service. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the names CAN-2003-0543 and CAN-2003-0544 to this issue. These erratum packages contain a patch provided by the OpenSSL group that protects against this issue. Because server applications are affected by this issue, users are advised to either restart all services that use OpenSSL functionality or reboot their systems after installing these updates. Red Hat would like to thank NISCC and Stephen Henson for their work on this vulnerability. These packages also include a patch from OpenSSL 0.9.6f which removes the calls to abort the process in certain circumstances. Red Hat would like to thank Patrik Hornik for notifying us of this issue.