CVE-2018-5773: markdown2 is vulnerable to cross-site scripting

CVE-2018-5773 · Severity: low · CVSS 3 · Published 2018-01-18

An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final '>' character from an IMG tag.

Technologies: markdown2 (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2018-5773 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2018-5773 being exploited in the wild.
How severe is CVE-2018-5773?
Low severity, with a CVSS score of 3, published 18 January 2018.
Which products and versions are affected?
markdown2 (PyPI) ECOSYSTEM:introduced=0,fixed=2.3.6.
Is there a fix for CVE-2018-5773?
Yes. markdown2 (PyPI): upgrade to 2.3.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2018-5773?
Check whether you run markdown2 (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

  • markdown2 (PyPI): upgrade to 2.3.6 or later
    pip install "markdown2>=2.3.6"

Affected products

  • markdown2 (PyPI) ECOSYSTEM:introduced=0,fixed=2.3.6

Identifiers

  • CVE-2018-5773
  • GHSA-p6h9-gw49-rqm4
  • PYSEC-2018-13

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