SB2020110430 - Red Hat Enterprise Linux 8 update for the varnish:6 module
Published: November 4, 2020
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) Reachable Assertion (CVE-ID: CVE-2019-15892)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a reachable assertion when parsing HTTP/1 requests. A remote attacker can send specially crafted HTTP/1 requests to the affected server and trigger application restart, resulting in a denial of service (DoS) attack.
2) Information disclosure (CVE-ID: CVE-2019-20637)
The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.
An issue was discovered in Varnish Cache before 6.0.5 LTS, 6.1.x and 6.2.x before 6.2.2, and 6.3.x before 6.3.1. It does not clear a pointer between the handling of one client request and the next request within the same connection. This sometimes causes information to be disclosed from the connection workspace, such as data structures associated with previous requests within this connection or VCL-related temporary headers.
3) Input validation error (CVE-ID: CVE-2020-11653)
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
An issue was discovered in Varnish Cache before 6.0.6 LTS, 6.1.x and 6.2.x before 6.2.3, and 6.3.x before 6.3.2. It occurs when communication with a TLS termination proxy uses PROXY version 2. There can be an assertion failure and daemon restart, which causes a performance loss.
Remediation
Install update from vendor's website.