D-Link DCS-1100/DCS-1130 Telnet Daemon getspnam hard-coded credentials

Summaryinfo

A vulnerability marked as critical has been reported in D-Link DCS-1100 and DCS-1130. This affects the function getspnam of the component Telnet Daemon. The manipulation leads to hard-coded credentials. This vulnerability is listed as CVE-2017-8415. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in D-Link DCS-1100 and DCS-1130 (the affected version is unknown) and classified as critical. This issue affects the function getspnam of the component Telnet Daemon. The manipulation with an unknown input leads to a hard-coded credentials vulnerability. Using CWE to declare the problem leads to CWE-798. The product contains hard-coded credentials, such as a password or cryptographic key, which it uses for its own inbound authentication, outbound communication to external components, or encryption of internal data. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

An issue was discovered on D-Link DCS-1100 and DCS-1130 devices. The device has a custom telnet daemon as a part of the busybox and retrieves the password from the shadow file using the function getspnam at address 0x00053894. Then performs a crypt operation on the password retrieved from the user at address 0x000538E0 and performs a strcmp at address 0x00053908 to check if the password is correct or incorrect. However, the /etc/shadow file is a part of CRAM-FS filesystem which means that the user cannot change the password and hence a hardcoded hash in /etc/shadow is used to match the credentials provided by the user. This is a salted hash of the string "admin" and hence it acts as a password to the device which cannot be changed as the whole filesystem is read only.

The weakness was presented 07/02/2019 as not defined mailinglist post (Bugtraq). It is possible to read the advisory at seclists.org. The identification of this vulnerability is CVE-2017-8415 since 05/02/2017. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/15/2023). The attack technique deployed by this issue is T1110.001 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

See VDB-136204, VDB-136205, VDB-136206 and VDB-136207 for similar entries. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• D-Link

Name

• DCS-1100
• DCS-1130

License

• commercial

Website

• Vendor: https://www.dlink.com/

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Entryinfo

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