CVE-2021-45402 : Vulnerability Insights and Analysis
Learn about CVE-2021-45402, a pointer leak vulnerability in the Linux kernel allowing local users to access sensitive address information. Find mitigation steps and patching advice here.
The check_alu_op() function in kernel/bpf/verifier.c in the Linux kernel through v5.16-rc5 did not properly update bounds, leading to a pointer leak vulnerability that allows local users to access potentially sensitive address information.
Understanding CVE-2021-45402
What is CVE-2021-45402?
The vulnerability stems from improper bounds updating in the check_alu_op() function, affecting the mov32 instruction in the Linux kernel up to version v5.16-rc5, enabling local users to retrieve sensitive address data.
The Impact of CVE-2021-45402
The vulnerability allows malicious local users to exploit a pointer leak flaw, potentially obtaining sensitive address information.
Technical Details of CVE-2021-45402
Vulnerability Description
The check_alu_op() function in kernel/bpf/verifier.c did not correctly update bounds when handling the mov32 instruction, leading to the pointer leak vulnerability.
Affected Systems and Versions
- Product: N/A
- Vendor: N/A
- Versions: Up to Linux kernel v5.16-rc5
Exploitation Mechanism
Attackers with local access can leverage the vulnerability to obtain sensitive address information through the pointer leak.
Mitigation and Prevention
Immediate Steps to Take
- Apply security patches provided by the Linux kernel maintainers promptly.
- Monitor official sources for updates and advisories regarding the vulnerability.
Long-Term Security Practices
- Enforce the principle of least privilege to minimize exposure to such vulnerabilities.
- Regularly update and patch systems to mitigate potential risks.
- Employ security best practices and conduct security audits periodically.
- Consider implementing additional security layers such as intrusion detection systems.
- Educate users on safe computing practices to prevent exploitation of vulnerabilities.
Patching and Updates
Software vendors typically release security patches and updates to address vulnerabilities like CVE-2021-45402. Stay informed about patches specific to the affected versions and apply them to secure your systems.