Debian Security Advisory

DLA-3023-1 puma -- LTS security update

Date Reported:
26 May 2022
Affected Packages:
Security database references:
In the Debian bugtracking system: Bug 946312, Bug 952766, Bug 1005391.
In Mitre's CVE dictionary: CVE-2019-16770, CVE-2020-5247, CVE-2022-23634.
More information:

Several security vulnerabilities have been discovered in puma, a web server for Ruby/Rack applications. These flaws may lead to information leakage due to not always closing response bodies, allowing untrusted input in a response header (HTTP Response Splitting) and thus potentially facilitating several other attacks like cross-site scripting. A poorly-behaved client could also use keepalive requests to monopolize Puma's reactor and create a denial of service attack.

For Debian 9 stretch, these problems have been fixed in version 3.6.0-1+deb9u2.

We recommend that you upgrade your puma packages.

For the detailed security status of puma please refer to its security tracker page at:

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: