SB2021080215 - HTTP request smuggling in Varnish Cache
Published: August 2, 2021
Security Bulletin ID
SB2021080215
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2021-36740)
The vulnerability allows a remote attacker to preform HTTP request smuggling attacks.
The vulnerability exists due to improper validation of HTTP/2 requests. A remote attacker can send a specially crafted HTTP/2 POST request with a large Content-Length header to the server and smuggle arbitrary HTTP headers.
Successful exploitation of vulnerability may allow an attacker to poison HTTP cache or bypass VCL authorization.
Remediation
Install update from vendor's website.