Security Experts:

Credential Leaking Vulnerabilities Impact Comba, D-Link Routers

Trustwave security researchers have discovered five new credential leaking vulnerabilities, two in a D-Link DSL modem and three in multiple Comba Telecom WiFi devices.

These issues, the researchers explain, involve the insecure storage of credentials. In three of these cases, cleartext credentials are available to all users with network access to the device.

Trustwave says multiple attempts to contact both D-Link and Comba to report these vulnerabilities remained unanswered. However, D-Link informed them several days ago that the bugs were patched.

The first of the vulnerabilities was found in the D-Link DSL-2875AL dual band wireless AC750 ADSL2+ modem. Versions 1.00.01 and 1.00.05 were found impacted, but others might be affected as well.

The issue is a password disclosure vulnerability in the file romfile.cfg, which is available to all users able to access the web-based management IP address, without authentication. The file is stored at https://[router ip address]/romfile.cfg and the password is in clear text.

The second issue also impacts the DSL-2877AL modem and consists of the username and password being listed in the source code of the router login page (https://[router ip address]/index.asp). An attacker could extract the credentials and access the victim’s ISP account.

The third vulnerability impacts the Comba AC2400 Wi-Fi Access Controller and consists of a configuration file being saved via an unauthenticated request for the URL https://[router ip address]/09/business/upgrade/upcfgAction.php?download=true.

The string contains the MD5 hash of the password to the device and can often be easily reversed, especially for simple or common passwords, Trustwave notes. Provided that SSH/Telnet is enabled, an attacker could abuse this to take over the filesystem of the device.

The two remaining vulnerabilities were found in the Comba AP2600-I WiFi Access Point (version A02,0202N00PD2).

The security researchers discovered that the source code of the web-based management login page includes the double MD5 hash of the plaintext username and password for the Access Point.

Additionally, the device supports loading https://[router ip address]/goform/downloadConfigFile without any form of authentication. An attacker could abuse this to download a file containing the username and password stored in plain text in a table named TABLE_SERVICE_INF.

“Since your router is the gateway in and out of your entire network it can potentially affect every user and system on that network. An attacker-controlled router can manipulate how your users resolve DNS hostnames to direct your users to malicious websites. An attacker-controlled router can deny access in and out of the network perhaps blocking your users from accessing important resources or blocking customers from accessing your website,” Trustwave concludes.

Related: FTC, D-Link Reach Agreement Over Device Security

Related: Critical Vulnerabilities Allow Takeover of D-Link Routers

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