CVE-2020-27539 : Exploit Details and Defense Strategies

A heap overflow vulnerability exists in Rostelecom CS-C2SHW 5.0.082.1, affecting the AgentUpdater service due to a self-written HTTP parser and builder. The issue allows for a heap buffer overflow during full parsing of HTTP responses.

Understanding CVE-2020-27539

This CVE involves a heap overflow vulnerability in a specific version of Rostelecom CS-C2SHW.

What is CVE-2020-27539?

The vulnerability arises from a heap overflow that occurs during the complete parsing of HTTP responses in the affected Rostelecom CS-C2SHW version.

The Impact of CVE-2020-27539

The vulnerability could potentially lead to a heap buffer overflow, allowing an out-of-bounds write. However, the default configuration restricts the camera to parse responses only from HTTPS URLs, making the vulnerable code unreachable without an additional bug.

Technical Details of CVE-2020-27539

This section provides more technical insights into the CVE.

Vulnerability Description

The vulnerability is a heap overflow issue that occurs during the full parsing of HTTP responses in Rostelecom CS-C2SHW 5.0.082.1 due to a self-written HTTP parser and builder.

Affected Systems and Versions

Affected Version: Rostelecom CS-C2SHW 5.0.082.1
Systems: AgentUpdater service

Exploitation Mechanism

The vulnerability allows for a heap buffer overflow, specifically an out-of-bounds write, when processing HTTP responses.

Mitigation and Prevention

Protecting systems from this vulnerability is crucial.

Immediate Steps to Take

Ensure that the camera only parses responses from trusted sources to prevent exploitation.
Regularly monitor for any unusual behavior that might indicate an attempted exploit.

Long-Term Security Practices

Implement secure coding practices to prevent buffer overflows and other memory-related vulnerabilities.
Conduct regular security assessments and audits to identify and address potential vulnerabilities.

Patching and Updates

Stay informed about security updates and patches released by the vendor to address this vulnerability.