CVE-2020-28951 Explained : Impact and Mitigation

OpenWrt's libuci before versions 18.06.9 and 19.x before 19.07.5 is susceptible to a use after free vulnerability when handling malicious package names.

Understanding CVE-2020-28951

This CVE identifies a specific vulnerability in OpenWrt's libuci library that could be exploited by attackers.

What is CVE-2020-28951?

CVE-2020-28951 is a use after free vulnerability in libuci in OpenWrt versions prior to 18.06.9 and 19.x before 19.07.5. The issue arises when processing malicious package names, specifically in uci_parse_package in file.c and uci_strdup in util.c.

The Impact of CVE-2020-28951

This vulnerability could allow an attacker to execute arbitrary code or cause a denial of service (DoS) condition on a system running the affected versions of OpenWrt.

Technical Details of CVE-2020-28951

OpenWrt's libuci vulnerability has specific technical aspects that are crucial to understand.

Vulnerability Description

The use after free vulnerability in libuci can be triggered by using malicious package names, leading to potential exploitation by threat actors.

Affected Systems and Versions

OpenWrt versions before 18.06.9 and 19.x before 19.07.5 are impacted by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting and using malicious package names to trigger the use after free condition in the uci_parse_package and uci_strdup functions.

Mitigation and Prevention

Protecting systems from CVE-2020-28951 requires immediate actions and long-term security measures.

Immediate Steps to Take

Update OpenWrt to versions 18.06.9 or 19.07.5 to mitigate the vulnerability.
Monitor for any unusual activities on the network that could indicate exploitation attempts.

Long-Term Security Practices

Regularly update and patch software to prevent known vulnerabilities from being exploited.
Implement network segmentation and access controls to limit the impact of potential attacks.

Patching and Updates

Apply patches provided by OpenWrt to address the use after free vulnerability in libuci.