SynopsisThe remote Debian host is missing a security-related update.
DescriptionA design flaw has been found in the TLS and SSL protocol that allows an attacker to inject arbitrary content at the beginning of a TLS/SSL connection. The attack is related to the way how TLS and SSL handle session renegotiations. CVE-2009-3555 has been assigned to this vulnerability.
As a partial mitigation against this attack, this apache2 update disables client-initiated renegotiations. This should fix the vulnerability for the majority of Apache configurations in use.
NOTE: This is not a complete fix for the problem. The attack is still possible in configurations where the server initiates the renegotiation. This is the case for the following configurations (the information in the changelog of the updated packages is slightly inaccurate) :
- The 'SSLVerifyClient' directive is used in a Directory or Location context.
- The 'SSLCipherSuite' directive is used in a Directory or Location context.
As a workaround, you may rearrange your configuration in a way that SSLVerifyClient and SSLCipherSuite are only used on the server or virtual host level.
A complete fix for the problem will require a protocol change. Further information will be included in a separate announcement about this issue.
In addition, this update fixes the following issues in Apache's mod_proxy_ftp :
- CVE-2009-3094 Insufficient input validation in the mod_proxy_ftp module allowed remote FTP servers to cause a denial of service (NULL pointer dereference and child process crash) via a malformed reply to an EPSV command.
- CVE-2009-3095 Insufficient input validation in the mod_proxy_ftp module allowed remote authenticated attackers to bypass intended access restrictions and send arbitrary FTP commands to an FTP server.
SolutionUpgrade the apache2 and apache2-mpm-itk packages.
For the oldstable distribution (etch), these problems have been fixed in version 2.2.3-4+etch11.
For the stable distribution (lenny), these problems have been fixed in version 2.2.9-10+lenny6. This version also includes some non-security bug fixes that were scheduled for inclusion in the next stable point release (Debian 5.0.4).
This advisory also provides updated apache2-mpm-itk packages which have been recompiled against the new apache2 packages.
Updated apache2-mpm-itk packages for the armel architecture are not included yet. They will be released as soon as they become available.