CVE-2019-9901 EnvoyProxy Envoy Missing HTTP URL path normalization

What is CVE-2019-9901?

CVE-2019-9901 is a medium-severity vulnerability in Envoyproxy Envoy, published on 25 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Envoy 1.9.0 and before does not normalize HTTP URL paths. A remote attacker may craft a relative path, e.g., something/../admin, to bypass access control, e.g., a block on /admin. A backend server could then interpret the non-normalized path and provide an attacker access beyond the scope provided for by the access control policy.

Weakness: CWE-706

Which versions are affected by CVE-2019-9901?

2 open source packages ship an affected version, including github.com/envoyproxy/envoy. It affects 1 product.

Products include Envoyproxy Envoy.

How do I fix CVE-2019-9901?

Upgrade github.com/envoyproxy/envoy to 1.9.1 or later.

Is CVE-2019-9901 being exploited?

There is no known exploitation of CVE-2019-9901 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
• GitHub advisory
• GitHub advisory
• How this page is made

Also known as GHSA-2wmf-p7f8-w42h, GHSA-xcx5-93pw-jw2w.