CVE-2021-22729

A CWE-259: Use of Hard-coded Password vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to R8 V3.4.0.1), EVlink Parking (EVW2 / EVF2 / EV.2 all versions prior to R8 V3.4.0.1), and EVlink Smart Wallbox (EVB1A all versions prior to R8 V3.4.0.1 ) that could allow an attacker to gain unauthorized administrative privileges when accessing to the charging station web server.

Weakness

The product contains a hard-coded password, which it uses for its own inbound authentication or for outbound communication to external components.

Affected Software

Extended Description

A hard-coded password typically leads to a significant authentication failure that can be difficult for the system administrator to detect. Once detected, it can be difficult to fix, so the administrator may be forced into disabling the product entirely. There are two main variations:

In the Inbound variant, a default administration account is created, and a simple password is hard-coded into the product and associated with that account. This hard-coded password is the same for each installation of the product, and it usually cannot be changed or disabled by system administrators without manually modifying the program, or otherwise patching the product. If the password is ever discovered or published (a common occurrence on the Internet), then anybody with knowledge of this password can access the product. Finally, since all installations of the product will have the same password, even across different organizations, this enables massive attacks such as worms to take place. The Outbound variant applies to front-end systems that authenticate with a back-end service. The back-end service may require a fixed password which can be easily discovered. The programmer may simply hard-code those back-end credentials into the front-end product. Any user of that program may be able to extract the password. Client-side systems with hard-coded passwords pose even more of a threat, since the extraction of a password from a binary is usually very simple.

Potential Mitigations

• For inbound authentication: apply strong one-way hashes to your 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 receiving an incoming password during authentication, take the hash of the password and compare it to the hash that you have saved.
• Use randomly assigned salts for each separate hash that you generate. 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

• http://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2021-194-06