Secunia

Greg MacManus has reported some vulnerabilities in WRT54G, which can be exploited malicious people to bypass certain security restrictions, cause a DoS (Denial of Service), or compromise a vulnerable system.

1) A validation error exists in the "POST" method handlers of the built-in web management httpd server when handing a negative "Content-Length" value. This can be exploited to cause the httpd to become unresponsive, and may cause the web management interface to be unavailable.

The vulnerability has been reported in firmware version 3.01.3, 3.03.6 and 4.00.7. All versions prior to 4.20.7 may also be affected.

2) A design error in upgrade.cgi can be exploited by an unauthenticated user to upload arbitrary firmware onto the router. The uploaded firmware will be saved on the router but will not take effect until the router is rebooted.

The vulnerability has been reported in firmware version 3.01.3, 3.03.6 and 4.00.7. All versions prior to 4.20.7 may also be affected.

3) A design error in restore.cgi can be exploited by an unauthenticated user to upload arbitrary configuration settings to router. The uploaded configuration settings will be saved on the router but will not take effect until the router is rebooted.

The vulnerability has been reported in firmware version 3.01.3, 3.03.6 and 4.00.7. All versions prior to 4.20.7 may also be affected.

4) The vulnerability is caused due to a boundary error in apply.cgi when sending a POST request to the page with a content length longer than 10000 bytes. This can be exploited to crash httpd and cause the web management interface to become unavailable, and may allow code execution with root privileges.

The vulnerability has been reported in firmware version 3.01.3 and 3.03.6. All versions prior to 4.20.7 may also be affected.

5) An authentication error in ezconfig.asp can be exploited by unauthenticated users to upload configuration settings to a vulnerable device if the fixed 256-byte XOR key used to encrypt the settings is known.

The vulnerability has been reported in firmware version 3.01.3 and 3.03.6.

Successful exploitation of the vulnerabilities requires the ability to connect to the web management interface.

Solution
Update firmware to version 4.20.7.

Provided and/or discovered by
Greg MacManus, iDEFENSE Labs.

Changelog
Further details available in Customer Area

Original Advisory
iDEFENSE:
http://www.idefense.com/application/poi/display?id=308&type=vulnerabilities
http://www.idefense.com/application/poi/display?id=307&type=vulnerabilities
http://www.idefense.com/application/poi/display?id=306&type=vulnerabilities
http://www.idefense.com/application/poi/display?id=305&type=vulnerabilities
http://www.idefense.com/application/poi/display?id=304&type=vulnerabilities

Deep Links
Links available in Customer Area