A weakness and two vulnerabilities have been reported in lighttpd, which can be exploited by malicious people to disclose potentially sensitive information, bypass certain security restrictions, and cause a DoS (Denial of Service).

1) A vulnerability is caused due to a memory leak within the "http_request_parse()" function when processing duplicate request headers and can be exploited to exhaust all available memory.

2) A vulnerability is caused due to the "mod_userdir" module not correctly handling filenames on case insensitive file systems. This can be exploited to e.g. disclose potentially sensitive information by sending requests with mixed upper and lowercase characters.

3) A weakness is caused due to lighttpd not decoding requests before matching them with rewrite and redirect rules. This can be exploited to e.g. bypass the rewrite and redirect rules.

The weakness and the vulnerabilities are reported in versions prior to 1.4.20.

Solution
Update to version 1.4.20.

Provided and/or discovered by
1) Reported by qhy in a lighttpd ticket.
2) Reported by anders1 in a lighttpd ticket.
3) Reported by gaetan.bisson in a lighttpd ticket.

Changelog
Further details available to Secunia VIM customers

Original Advisory
1) http://trac.lighttpd.net/trac/ticket/1774
http://www.lighttpd.net/security/lighttpd_sa_2008_07.txt
2) http://www.lighttpd.net/security/lighttpd_sa_2008_06.txt
3) http://www.lighttpd.net/security/lighttpd_sa_2008_05.txt

Deep Links
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