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Security Advisories: GSA_kwCzR0hTQS1qaDg1LXd3djktMjRods4AAzV0
Any file can be included with the pymdown-snippets extension
Summary
Arbitrary file read when using include file syntax.
Details
By using the syntax --8<--"/etc/passwd"
or --8<--"/proc/self/environ"
the content of these files will be rendered in the generated documentation. Additionally, a path relative to a specified, allowed base path can also be used to render the content of a file outside the specified base paths: --8<-- "../../../../etc/passwd"
.
Within the Snippets extension, there exists a base_path
option but the implementation is vulnerable to Directory Traversal.
The vulnerable section exists in get_snippet_path(self, path)
lines 155 to 174 in snippets.py.
base = "docs"
path = "/etc/passwd"
filename = os.path.join(base,path) # Filename is now /etc/passwd
PoC
import markdown
payload = "--8<-- \"/etc/passwd\""
html = markdown.markdown(payload, extensions=['pymdownx.snippets'])
print(html)
Impact
Any readable file on the host where the plugin is executing may have its content exposed. This can impact any use of Snippets that exposes the use of Snippets to external users.
It is never recommended to use Snippets to process user-facing, dynamic content. It is designed to process known content on the backend under the control of the host, but if someone were to accidentally enable it for user-facing content, undesired information could be exposed.
Suggestion
Specified snippets should be restricted to the configured, specified base paths as a safe default. Allowing relative or absolute paths that escape the specified base paths would need to be behind a feature switch that must be opt-in and would be at the developer's own risk.
Permalink: https://github.com/advisories/GHSA-jh85-wwv9-24hvJSON: https://advisories.ecosyste.ms/api/v1/advisories/GSA_kwCzR0hTQS1qaDg1LXd3djktMjRods4AAzV0
Source: GitHub Advisory Database
Origin: Unspecified
Severity: High
Classification: General
Published: 12 months ago
Updated: 6 months ago
CVSS Score: 7.5
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Identifiers: GHSA-jh85-wwv9-24hv, CVE-2023-32309
References:
- https://github.com/facelessuser/pymdown-extensions/security/advisories/GHSA-jh85-wwv9-24hv
- https://github.com/facelessuser/pymdown-extensions/commit/b7bb4878d6017c03c8dc97c42d8d3bb6ee81db9d
- https://github.com/facelessuser/pymdown-extensions/releases/tag/10.0
- https://nvd.nist.gov/vuln/detail/CVE-2023-32309
- https://github.com/advisories/GHSA-jh85-wwv9-24hv
Blast Radius: 29.5
Affected Packages
pypi:pymdown-extensions
Dependent packages: 177Dependent repositories: 8,465
Downloads: 3,653,279 last month
Affected Version Ranges: >= 1.5, < 10.0
Fixed in: 10.0
All affected versions: 1.6.1, 3.2.1, 4.5.1, 4.9.1, 4.9.2, 4.10.1, 4.10.2, 6.2.1, 8.0.1, 8.1.1, 9.9.1, 9.9.2
All unaffected versions: 1.0.0, 1.0.1, 10.0.1, 10.2.1, 10.3.1, 10.7.1, 10.8.1