CVE-2021-29258 Denial of service in n/a

What is CVE-2021-29258?

CVE-2021-29258 is a high-severity denial of service vulnerability in Envoyproxy Envoy, published on 20 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-617

Which versions are affected by CVE-2021-29258?

1 open source package ship an affected version, including envoy. It affects 1 product.

Products include Envoyproxy Envoy.

How do I fix CVE-2021-29258?

Upgrade envoy to a fixed version for your release line: 1.14.7, 1.15.4, 1.16.3 or 1.17.2.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-29258 being exploited?

There is no known exploitation of CVE-2021-29258 in the wild and no public exploit code.

Other vulnerabilities in Envoyproxy Envoy

• CVE-2022-29226 Trivial authentication bypass in Envoy Critical 10.0
• CVE-2019-18801 Memory corruption in n/a Critical 9.8
• CVE-2019-18802 Security feature bypass in n/a Critical 9.8
• CVE-2020-35470 Information disclosure in n/a High 8.8
• CVE-2024-23324 Envoy ext auth can be bypassed when Proxy protocol filter sets invalid UTF-8 metadata High 8.6

All Envoyproxy Envoy vulnerabilities

Sources

• CVE record
• NVD
• OSV
• How this page is made

Also known as BIT-envoy-2021-29258.