Arch Linux Security Advisory ASA-202105-25

Severity: Medium
Date    : 2021-05-25
CVE-ID  : CVE-2021-29622
Package : prometheus
Type    : open redirect
Remote  : Yes
Link    :


The package prometheus before version 2.27.1-1 is vulnerable to open


Upgrade to 2.27.1-1.

# pacman -Syu "prometheus>=2.27.1-1"

The problem has been fixed upstream in version 2.27.1.


The issue can be mitigated by using the --web.external-url= flag with a
path (e.g. --web.external-url=


A security issue has been found in Prometheus before version 2.27.1. 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
(e.g., they can be redirected to an
arbitrary URL. E.g. if a user visits, they will be
redirected to

Note: Users who use a --web.external-url= flag with a path (e.g.
--web.external-url= are not affected.


A remote attacker can use crafted URLs to redirect victims from a
Prometheus server instance to an arbitrary address.