CVE-2021-35209 : Exploit Details and Defense Strategies
Discover the security vulnerability in Zimbra Collaboration Suite 8.8 and 9.x versions that allows unauthorized data access. Learn the impact, technical details, and mitigation steps.
An issue was discovered in ProxyServlet.java in the /proxy servlet in Zimbra Collaboration Suite 8.8 before 8.8.15 Patch 23 and 9.x before 9.0.0 Patch 16. The value of the X-Host header overwrites the value of the Host header in proxied requests.
Understanding CVE-2021-35209
This CVE highlights a security vulnerability in Zimbra Collaboration Suite that could lead to unauthorized data exposure or manipulation.
What is CVE-2021-35209?
The vulnerability stems from improper handling of the X-Host header in proxied requests, allowing an attacker to overwrite the Host header's value without proper validation.
The Impact of CVE-2021-35209
Exploitation of this vulnerability could result in unauthorized access to sensitive information or the manipulation of data being proxied by Zimbra Collaboration Suite.
Technical Details of CVE-2021-35209
The technical details of this CVE include:
Vulnerability Description
The issue arises from the X-Host header's value overriding the Host header value in proxied requests, bypassing whitelist validation.
Affected Systems and Versions
Zimbra Collaboration Suite versions 8.8 before 8.8.15 Patch 23 and 9.x before 9.0.0 Patch 16 are impacted by this vulnerability.
Exploitation Mechanism
By manipulating the X-Host header, threat actors can potentially perform various attacks, including data interception and modification.
Mitigation and Prevention
To mitigate the risks associated with CVE-2021-35209, follow these guidelines:
Immediate Steps to Take
- Update Zimbra Collaboration Suite to the latest patched version that addresses this vulnerability.
- Validate and sanitize headers to prevent unauthorized overrides.
Long-Term Security Practices
- Regularly monitor and audit network traffic for any suspicious activities.
- Implement strong access controls and authentication mechanisms.
Patching and Updates
Always keep your Zimbra Collaboration Suite up to date with the latest patches and security fixes to protect against known vulnerabilities.