Marsh Ray and Steve Dispensa discovered a flaw in the TLS and SSLv3 protocols. If an attacker could perform a man in the middle attack at the start of a TLS connection, the attacker could inject arbitrary content at the beginning of the user’s session. The flaw is with TLS renegotiation and potentially affects any software that supports this feature. Attacks against the HTTPS protocol are known, with the severity of the issue depending on the safeguards used in the web application. Until the TLS protocol and underlying libraries are adjusted to defend against this vulnerability, a partial, temporary workaround has been applied to Apache that disables client initiated TLS renegotiation. This update does not protect against server initiated TLS renegotiation when using SSLVerifyClient and SSLCipherSuite on a per Directory or Location basis. Users can defend againt server inititiated TLS renegotiation attacks by adjusting their Apache configuration to use SSLVerifyClient and SSLCipherSuite only on the server or virtual host level. (CVE-2009-3555)
It was discovered that mod_proxy_ftp in Apache did not properly sanitize its input when processing replies to EPASV and PASV commands. An attacker could use this to cause a denial of service in the Apache child process. (CVE-2009-3094)
19 November 2009
A security issue affects these releases of Ubuntu and its derivatives:
Marsh Ray and Steve Dispensa discovered a flaw in the TLS and SSLv3 protocols. If an attacker could perform a man in the middle attack at the start of a TLS connection, the attacker could inject arbitrary content at the beginning of the user’s session. The flaw is with TLS renegotiation and potentially affects any software that supports this feature. Attacks against the HTTPS protocol are known, with the severity of the issue depending on the safeguards used in the web application. Until the TLS protocol and underlying libraries are adjusted to defend against this vulnerability, a partial, temporary workaround has been applied to Apache that disables client initiated TLS renegotiation. This update does not protect against server initiated TLS renegotiation when using SSLVerifyClient and SSLCipherSuite on a per Directory or Location basis. Users can defend againt server inititiated TLS renegotiation attacks by adjusting their Apache configuration to use SSLVerifyClient and SSLCipherSuite only on the server or virtual host level. (CVE-2009-3555)
It was discovered that mod_proxy_ftp in Apache did not properly sanitize its input when processing replies to EPASV and PASV commands. An attacker could use this to cause a denial of service in the Apache child process. (CVE-2009-3094)
Another flaw was discovered in mod_proxy_ftp. If Apache is configured as a reverse proxy, an attacker could send a crafted HTTP header to bypass intended access controls and send arbitrary commands to the FTP server. (CVE-2009-3095)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system upgrade is sufficient to effect the necessary changes.
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