CVE-2020-27540 : What You Need to Know

A Bash injection vulnerability and bypass of signature verification in Rostelecom CS-C2SHW 5.0.082.1 camera allow unauthorized execution of firmware updates.

Understanding CVE-2020-27540

This CVE involves a security flaw in the Rostelecom CS-C2SHW 5.0.082.1 camera that enables a Bash injection attack and circumvention of signature verification.

What is CVE-2020-27540?

The vulnerability allows an attacker to manipulate the firmware update process by inserting malicious commands via the fw-sign parameter in the configuration file read from an SD card.

The Impact of CVE-2020-27540

Unauthorized execution of firmware updates
Potential for arbitrary code execution

Technical Details of CVE-2020-27540

The technical aspects of the CVE provide insight into the vulnerability's specifics.

Vulnerability Description

The camera's firmware update process is susceptible to Bash injection, enabling attackers to run unauthorized firmware updates.

Affected Systems and Versions

System: Rostelecom CS-C2SHW 5.0.082.1 camera
Versions: All versions are affected

Exploitation Mechanism

The camera reads firmware update configuration from an SD card file
Malicious commands are inserted via the fw-sign parameter
Firmware update is automatically executed if a specific file is present on the SD card

Mitigation and Prevention

Protecting systems from CVE-2020-27540 requires immediate actions and long-term security practices.

Immediate Steps to Take

Disable automatic firmware updates
Implement strict file validation checks
Monitor SD card insertions for suspicious activity

Long-Term Security Practices

Regular security audits and code reviews
Train users on secure SD card usage
Implement secure firmware update mechanisms

Patching and Updates

Apply patches provided by Rostelecom for the affected camera
Stay informed about security updates and best practices