A vulnerability was found in Linksys WRT54G 4.21.5. It has been rated as critical. Affected by this issue is the function validateservicesport of the file /apply.cgi of the component POST Parameter Handler. The manipulation of the argument servicesarray leads to stack-based buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Linksys WRT54G v4.21.5 has a stack overflow vulnerability in getmergemac function.
The UPnP IGD implementation in the Broadcom UPnP stack on the Cisco Linksys WRT54G with firmware before 4.30.5, WRT54GS v1 through v3 with firmware before 4.71.1, and WRT54GS v4 with firmware before 1.06.1 allows remote attackers to establish arbitrary port mappings by sending a UPnP AddPortMapping action in a SOAP request to the WAN interface, related to an "external forwarding" vulnerability.
The Linksys WRT54G router stores passwords and keys in cleartext in the Config.bin file, which might allow remote authenticated users to obtain sensitive information via an HTTP request for the top-level Config.bin URI.
The Linksys WRT54G router allows remote attackers to cause a denial of service (device restart) via a long username and password to the FTP interface.
The Linksys WRT54G router has "admin" as its default FTP password, which allows remote attackers to access sensitive files including nvram.cfg, a file that lists all HTML documents, and an ELF executable file.
The FTP server on the Linksys WRT54G 7 router with 7.00.1 firmware does not verify authentication credentials, which allows remote attackers to establish an FTP session by sending an arbitrary username and password.
The web interface on the Linksys WRT54g router with firmware 1.00.9 does not require credentials when invoking scripts, which allows remote attackers to perform arbitrary administrative actions via a direct request to (1) Advanced.tri, (2) AdvRoute.tri, (3) Basic.tri, (4) ctlog.tri, (5) ddns.tri, (6) dmz.tri, (7) factdefa.tri, (8) filter.tri, (9) fw.tri, (10) manage.tri, (11) ping.tri, (12) PortRange.tri, (13) ptrigger.tri, (14) qos.tri, (15) rstatus.tri, (16) tracert.tri, (17) vpn.tri, (18) WanMac.tri, (19) WBasic.tri, or (20) WFilter.tri. NOTE: the Security.tri vector is already covered by CVE-2006-5202.
Linksys WRT54G 3.01.03, 3.03.6, 4.00.7, and possibly other versions before 4.20.7, does not verify user authentication until after an HTTP POST request has been processed, which allows remote attackers to (1) modify configuration using restore.cgi or (2) upload new firmware using upgrade.cgi.
Linksys WRT54G router allows remote attackers to cause a denial of service (CPU consumption and server hang) via an HTTP POST request with a negative Content-Length value.