CVE-2021-41146: Arbitrary command execution on Windows via qutebrowserurl: URL handler

CVE-2021-41146 · Severity: low · CVSS 3.1 · Published 2021-10-21

qutebrowser is an open source keyboard-focused browser with a minimal GUI. Starting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers a `qutebrowserurl:` URL handler. With certain applications, opening a specially crafted `qutebrowserurl:...` URL can lead to execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`. Only Windows installs where qutebrowser is registered as URL handler are affected. The issue has been fixed in qutebrowser v2.4.0. The fix also adds additional hardening for potential similar issues on Linux (by adding the new --untrusted-args flag to the .desktop file), though no such vulnerabilities are known.

Technologies: qutebrowser (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2021-41146 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2021-41146 being exploited in the wild.
How severe is CVE-2021-41146?
Low severity, with a CVSS score of 3.1, published 21 October 2021.
Which products and versions are affected?
qutebrowser (PyPI) ECOSYSTEM:introduced=1.7.0,fixed=2.4.0, GIT:introduced=0,fixed=8f46ba3f6dc7b18375f7aa63c48a1fe461190430|ECOSYSTEM:introduced=0,fixed=1.8.0,introduced=2.0.0,fixed=2.4.0.
Is there a fix for CVE-2021-41146?
Yes. qutebrowser (PyPI): upgrade to 2.4.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2021-41146?
Check whether you run qutebrowser (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • qutebrowser (PyPI): upgrade to 2.4.0 or later
    pip install "qutebrowser>=2.4.0"

Affected products

  • qutebrowser (PyPI) ECOSYSTEM:introduced=1.7.0,fixed=2.4.0, GIT:introduced=0,fixed=8f46ba3f6dc7b18375f7aa63c48a1fe461190430|ECOSYSTEM:introduced=0,fixed=1.8.0,introduced=2.0.0,fixed=2.4.0

Identifiers

  • CVE-2021-41146
  • GHSA-vw27-fwjf-5qxm
  • PYSEC-2021-382

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