CVE-2021-39206 Incorrect Authorization with specially crafted requests
Attackers can bypass authorization policies in Pomerium using crafted requests when path prefix policies are enabled, allowing unauthorized access.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-39206?
CVE-2021-39206 is a high-severity missing authorization vulnerability in Envoyproxy Envoy, published on 9 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Pomerium is an open source identity-aware access proxy. Envoy, which Pomerium is based on, contains two authorization related vulnerabilities CVE-2021-32777 and CVE-2021-32779. This may lead to incorrect routing or authorization policy decisions. With specially crafted requests, incorrect authorization or routing decisions may be made by Pomerium. Pomerium v0.14.8 and v0.15.1 contain an upgraded envoy binary with these vulnerabilities patched. This issue can only be triggered when using path prefix based policy. Removing any such policies should provide mitigation.
Weakness: CWE-863
Which versions are affected by CVE-2021-39206?
5 open source packages ship an affected version, including envoy and github.com/pomerium/pomerium. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
envoy Bitnami | All versions | 1.16.5, 1.17.4, 1.18.4, 1.19.1 |
github.com/pomerium/pomerium Go | From 0.11.0 | 0.14.8 |
github.com/pomerium/pomerium Go | From 0.11.0 | 0.14.8 |
github.com/pomerium/pomerium Go | From 0.15.0 | 0.15.1 |
github.com/pomerium/pomerium Go | From 0.15.0 | 0.15.1 |
Products include Envoyproxy Envoy, Pomerium Pomerium.
How do I fix CVE-2021-39206?
Upgrade envoy to a fixed version for your release line: 1.16.5, 1.17.4, 1.18.4 or 1.19.1.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2021-39206 being exploited?
There is no known exploitation of CVE-2021-39206 in the wild and no public exploit code.
Other vulnerabilities in Envoyproxy Envoy
Sources
Also known as BIT-envoy-2021-39206, GHSA-cfc2-wjcm-c8fm.