The Apache HTTP Server Project Thursday warned that several security holes in the Apache source code are being actively exploited on the Internet. It is urging IT managers to urgently upgrade to version 1.3.27 or 2.0.43 or higher.
This is the second warning from the open-source project, which is used by more than 60 percent of Web servers on the Net. Because most of the vulnerable code is shared between the Apache and Apache-Perl packages, the flaws are shared as well, Apache warned.
The latest warning, posted on the BugTraq mailing list, highlights a scoreboard memory segment overwriting vulnerability that could lead to denial-of-service (DoS) attacks.
The vulnerability allows an attacker to execute code under the Apache UID to exploit the Apache shared memory scoreboard format and send a signal to any process as root or cause a local denial of service attack, Apache warned.
Apache said the recent Linux/Apache/mod_ssl/OpenSSL slapper worm continues to exploit a problem in the OpenSSLsource code and not a problem specific to the Apache HTTP Server source code. Affected users are urged to upgrade the OpenSSL library and not the HTTP Server.
"If you are running an SSL-enabled web server using OpenSSL, upgrade to at least version 0.9.6e of OpenSSL and recompile all applications that use OpenSSL," the organization said.
Other vulnerabilities still being exploited on servers that haven't been upgraded include:
- A cross-site scripting bug in the default 404 page of any Web server hosted on a domain that allows wildcard DNS lookups
- Possible overflows in the utility ApacheBench (ab) which could be exploited by a malicious server
- A race condition in the htpasswd and htdigest program that enables a malicious local user to read or even modify the contents of a password file or easily create and overwrite files as the user running the htpasswd (or htdigest respectively) program
- htpasswd and htdigest in Apache 2.0a9, 1.3.14, and others allow local users to overwrite arbitrary files via a symlink attack
- Several buffer overflows in the ApacheBench (ab) utility that could be exploited by a remote server returning very long strings