Several vulnerabilities have been discovered in PHP version 4, a server-side, HTML-embedded scripting language. The Common Vulnerabilities and Exposures project identifies the following problems:
The session_start function allows remote attackers to insert arbitrary attributes into the session cookie via special characters in a cookie that is obtained from various parameters.
A denial of service was possible through a malicious script abusing the glob() function.
Certain maliciously constructed input to the wordwrap() function could lead to a denial of service attack.
Large len values of the stspn() or strcspn() functions could allow an attacker to trigger integer overflows to expose memory or cause denial of service.
The escapeshellcmd API function could be attacked via incomplete multibyte chars.
For the stable distribution (etch), these problems have been fixed in version 6:4.4.4-8+etch6.
The php4 packages are no longer present the unstable distribution (sid).
We recommend that you upgrade your php4 package.