CVE-2020-4037 json
Open Redirect in OAuth2 Proxy
published 6y ago modified 2mo ago also BIT-oauth2-proxy-2020-4037 , EUVD-2021-2449 , GHSA-5m6c-jp6f-2vcv
- cvss
- 4.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 59%
- public exploits
- 0
- none known
Summary
In OAuth2 Proxy from version 5.1.1 and less than version 6.0.0, users can provide a redirect address for the proxy to send the authenticated user to at the end of the authentication flow. This is expected to be the original URL that the user was trying to access. This redirect URL is checked within the proxy and validated before redirecting the user to prevent malicious actors providing redirects to potentially harmful sites. This has been fixed in version 6.0.0.
Patch / fix
- go github.com/oauth2-proxy/oauth2-proxy 6.0.0
- bitnami oauth2-proxy 6.0.0
- oauth2_proxy_project oauth2_proxy 6.0.0
Is CVE-2020-4037 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.90% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N |
| GitHub | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N |
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N |
| NVD | 2.0 | 5.8 | AV:N/AC:M/Au:N/C:P/I:P/A:N |
| OSV | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/oauth2-proxy/oauth2-proxy | >=5.1.1, <6.0.0 |
6.0.0 |
| bitnami | oauth2-proxy | >=5.1.1, <6.0.0 |
6.0.0 |
Affected products
- OAuth2 Proxy OAuth2 Proxy
Classification
- Weakness
-
- CWE-601 URL Redirection to Untrusted Site
References
-
github.com
/oauth2-proxy/oauth2-proxy/commit/ee5662e0f5001d76ec76562bb605abbd07c266a2
web, patch, third-party-advisory, advisory
-
github.com
/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-5m6c-jp6f-2vcv
web, third-party-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2020-4037
advisory, web
-
github.com
/oauth2-proxy/oauth2-proxy/releases/tag/v6.0.0
web
Sources
- CVE List CVE-2020-4037
- GitHub Advisory GHSA-5m6c-jp6f-2vcv
- NVD CVE-2020-4037
- OSV BIT-oauth2-proxy-2020-4037
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.