Amcrest IPM-721S V2.420.AC00.16.R.20160909 devices have default credentials that are hardcoded in the firmware and can be extracted by anyone who reverses the firmware to identify them. If the firmware version V2.420.AC00.16.R 9/9/2016 is dissected using binwalk tool, one obtains a _user-x.squashfs.img.extracted archive which contains the filesystem set up on the device that many of the binaries in the /usr folder. The binary sonia is the one that has the vulnerable function that sets up the default credentials on the device. If one opens this binary in IDA-pro, one will notice that this follows a ARM little endian format. The function sub_3DB2FC in IDA pro is identified to be setting up the values at address 0x003DB5A6. The sub_5C057C then sets this value and adds it to the Configuration files in /mnt/mtd/Config/Account1 file.
Weakness
The product contains hard-coded credentials, such as a password or cryptographic key.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Ipm-721s_firmware |
Amcrest |
* |
2.420.ac00.16.r.20160909 (including) |
Extended Description
There are two main variations:
Potential Mitigations
- For outbound authentication: store passwords, keys, and other credentials outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible [REF-7].
- In Windows environments, the Encrypted File System (EFS) may provide some protection.
- For inbound authentication using passwords: apply strong one-way hashes to passwords and store those hashes in a configuration file or database with appropriate access control. That way, theft of the file/database still requires the attacker to try to crack the password. When handling an incoming password during authentication, take the hash of the password and compare it to the saved hash.
- Use randomly assigned salts for each separate hash that is generated. This increases the amount of computation that an attacker needs to conduct a brute-force attack, possibly limiting the effectiveness of the rainbow table method.
- For front-end to back-end connections: Three solutions are possible, although none are complete.
References