Open Redirect in Prometheus

CVE-2021-29622

Prometheus is an open-source monitoring system and time series database. In 2.23.0, Prometheus changed its default UI to the New ui. To ensure a seamless transition, the URL's prefixed by /new redirect to /. Due to a bug in the code, it is possible for an attacker to craft an URL that can redirect to any other URL, in the /new endpoint. If a user visits a prometheus server with a specially crafted address, they can be redirected to an arbitrary URL. The issue was patched in the 2.26.1 and 2.27.1 releases. In 2.28.0, the /new endpoint will be removed completely. The workaround is to disable access to /new via a reverse proxy in front of Prometheus.

Vulnerability class: Open Redirect

EPSS: 0.196 (97.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

Affected products

  • Prometheus — versions 2.27.0, >= 2.23.0, < 2.27.1

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-29622?
CVE-2021-29622 is a medium-severity vulnerability in Prometheus, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.5/10. Published 2021-05-19.
How severe is CVE-2021-29622?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2021-29622 known to be exploited?
10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.