CVE-2020-8843 : Security Advisory and Response
Discover the Istio vulnerability in versions 1.3 through 1.3.6 allowing bypassing of Mixer policy configurations. Learn about the impact, affected systems, exploitation, and mitigation steps.
An issue was discovered in Istio 1.3 through 1.3.6 that allows bypassing a specifically configured Mixer policy by manipulating the x-istio-attributes header.
Understanding CVE-2020-8843
This CVE highlights a vulnerability in Istio versions 1.3 through 1.3.6 that could be exploited to bypass Mixer policy configurations.
What is CVE-2020-8843?
The vulnerability in Istio allows the x-istio-attributes header to influence policy decisions when Mixer policy selectively applies to a source equal to ingress. Exploiting this flaw requires encoding a source.uid in the header, which is disabled by default in Istio 1.3 and 1.4.
The Impact of CVE-2020-8843
This vulnerability could potentially lead to unauthorized bypassing of Mixer policy configurations, compromising the security and integrity of Istio deployments.
Technical Details of CVE-2020-8843
This section provides more in-depth technical insights into the CVE.
Vulnerability Description
The vulnerability in Istio versions 1.3 through 1.3.6 allows for the manipulation of the x-istio-attributes header to influence policy decisions, potentially bypassing Mixer policy configurations.
Affected Systems and Versions
- Affected Versions: Istio 1.3 through 1.3.6
- Systems: Istio deployments with the vulnerable versions
Exploitation Mechanism
- Exploiting the vulnerability requires encoding a source.uid in the x-istio-attributes header
- This feature is disabled by default in Istio 1.3 and 1.4
Mitigation and Prevention
Protecting systems from CVE-2020-8843 involves immediate steps and long-term security practices.
Immediate Steps to Take
- Update Istio to a non-vulnerable version
- Implement strict input validation to prevent header manipulation
Long-Term Security Practices
- Regularly monitor Istio security advisories and updates
- Conduct security audits to identify and address vulnerabilities proactively
Patching and Updates
- Apply patches provided by Istio to fix the vulnerability
- Stay informed about security best practices and updates from Istio