CVE-2020-5291 Explained : Impact and Mitigation

Bubblewrap (bwrap) before version 0.4.1, if installed in setuid mode and the kernel supports unprivileged user namespaces, then the

bwrap --userns2

option can be used to make the setuid process keep running as root while being traceable. This can in turn be used to gain root permissions. This vulnerability affects various Linux distributions and has a CVSS base score of 7.2.

Understanding CVE-2020-5291

Bubblewrap vulnerability allowing privilege escalation via user namespaces.

What is CVE-2020-5291?

Bubblewrap vulnerability in setuid mode with unprivileged user namespaces support, allowing root access.

The Impact of CVE-2020-5291

High Severity: CVSS base score of 7.2
Privilege Escalation: Attackers can gain root permissions.

Technical Details of CVE-2020-5291

Bubblewrap vulnerability details.

Vulnerability Description

Incorrect use of privileged APIs (CWE-648)

Affected Systems and Versions

Product: Bubblewrap
Vendor: Containers
Versions Affected: < 0.4.1

Exploitation Mechanism

Attack Complexity: High
Attack Vector: Local
Privileges Required: Low
User Interaction: Required

Mitigation and Prevention

Steps to mitigate and prevent exploitation of CVE-2020-5291.

Immediate Steps to Take

Update Bubblewrap to version 0.4.1 or higher.
Disable setuid mode if not required.

Long-Term Security Practices

Regularly update software and dependencies.
Monitor security advisories for patches and updates.

Patching and Updates

Apply patches promptly to fix known vulnerabilities.