CVE-2024-39315 Pomerium exposed OAuth2 access and ID tokens in user info endpoint response

What is CVE-2024-39315?

CVE-2024-39315 is a medium-severity vulnerability in pomerium, published on 2 Jul 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Pomerium is an identity and context-aware access proxy. Prior to version 0.26.1, the Pomerium user info page (at `/.pomerium`) unintentionally included serialized OAuth2 access and ID tokens from the logged-in user's session. These tokens are not intended to be exposed to end users. This issue may be more severe in the presence of a cross-site scripting vulnerability in an upstream application proxied through Pomerium. If an attacker could insert a malicious script onto a web page proxied through Pomerium, that script could access these tokens by making a request to the `/.pomerium` endpoint. Upstream applications that authenticate only the ID token may be vulnerable to user impersonation using a token obtained in this manner. Note that an OAuth2 access token or ID token by itself is not sufficient to hijack a user's Pomerium session. Upstream applications should not be vulnerable to user impersonation via these tokens provided the application verifies the Pomerium JWT for each request, the connection between Pomerium and the application is secured by mTLS, or the connection between Pomerium and the application is otherwise secured at the network layer. The issue is patched in Pomerium v0.26.1. No known workarounds are available.

Weakness: CWE-201

Which versions are affected by CVE-2024-39315?

3 open source packages ship an affected version, including github.com/pomerium/pomerium. It affects 1 product.

Products include Pomerium Pomerium.

How do I fix CVE-2024-39315?

Upgrade github.com/pomerium/pomerium to 0.26.1 or later.

Is CVE-2024-39315 being exploited?

There is no known exploitation of CVE-2024-39315 in the wild and no public exploit code.

Other vulnerabilities in pomerium

• CVE-2023-33189 Incorrect Authorization with specially crafted requests Critical 10.0
• CVE-2022-24797 Exposure of Sensitive Information in Pomerium Medium 6.5
• CVE-2021-29651 JWT leak via Open Redirect in Programmatic access Medium 6.1
• CVE-2021-29652 pomerium_signature is not verified in middleware in github.com/pomerium/pomerium Medium 6.1
• CVE-2021-41230 OIDC claims not updated from Identity Provider in Pomerium Medium 5.3

Sources

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

Also known as GHSA-rrqr-7w59-637v, GO-2024-2965.