SynopsisThe remote Scientific Linux host is missing one or more security updates.
DescriptionCVE-2009-1891 httpd: possible temporary DoS (CPU consumption) in mod_deflate
CVE-2009-3094 httpd: NULL pointer defer in mod_proxy_ftp caused by crafted EPSV and PASV reply
CVE-2009-3095 httpd: mod_proxy_ftp FTP command injection via Authorization HTTP header
CVE-2009-3555 TLS: MITM attacks via session renegotiation
A flaw was found in the way the TLS/SSL (Transport Layer Security/Secure Sockets Layer) protocols handle session renegotiation.
A man-in-the-middle attacker could use this flaw to prefix arbitrary plain text to a client's session (for example, an HTTPS connection to a website). This could force the server to process an attacker's request as if authenticated using the victim's credentials. This update partially mitigates this flaw for SSL sessions to HTTP servers using mod_ssl by rejecting client-requested renegotiation.
Note: This update does not fully resolve the issue for HTTPS servers.
An attack is still possible in configurations that require a server-initiated renegotiation. Refer to the following Knowledgebase article for further information:
A denial of service flaw was found in the Apache mod_deflate module.
This module continued to compress large files until compression was complete, even if the network connection that requested the content was closed before compression completed. This would cause mod_deflate to consume large amounts of CPU if mod_deflate was enabled for a large file. (CVE-2009-1891) - SL4 only
A NULL pointer dereference flaw was found in the Apache mod_proxy_ftp module. A malicious FTP server to which requests are being proxied could use this flaw to crash an httpd child process via a malformed reply to the EPSV or PASV commands, resulting in a limited denial of service. (CVE-2009-3094)
A second flaw was found in the Apache mod_proxy_ftp module. In a reverse proxy configuration, a remote attacker could use this flaw to bypass intended access restrictions by creating a carefully-crafted HTTP Authorization header, allowing the attacker to send arbitrary commands to the FTP server. (CVE-2009-3095)
After installing the updated packages, the httpd daemon must be restarted for the update to take effect.
SolutionUpdate the affected packages.