CVE-2021-29258: High severity envoy proxy vulnerability
A null reference vulnerability was found in all versions of Envoy up to 1.17.2. If an attacker can craft a HTTP2 request that specifies an empty metadata map[1], then envoy will attempt to process this and crash, resulting in a denial of service.
[1] - https://github.com/envoyproxy/envoy/blob/main/source/docs/h2metadata.md
Other sources
An issue was discovered in Envoy 1.14.0. There is a remotely exploitable crash for HTTP2 Metadata, because an empty METADATA map triggers a Reachable Assertion.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is CVE-2021-29258?
CVE-2021-29258 is a vulnerability discovered in Envoy 1.14.0 that allows for a remotely exploitable crash for HTTP2 Metadata.
How severe is CVE-2021-29258?
CVE-2021-29258 has a severity rating of 7.5 (high).
How does CVE-2021-29258 occur?
CVE-2021-29258 occurs when an empty METADATA map triggers a Reachable Assertion in Envoy.
Which versions of Envoy are affected by CVE-2021-29258?
Envoy versions 1.14.6, 1.15.3, 1.16.2, and 1.17.1 are affected by CVE-2021-29258.
How can CVE-2021-29258 be fixed or mitigated?
To fix CVE-2021-29258, upgrade to Envoy version 1.17.2 or later.