CVE-2023-32309

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)

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.

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.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2023-32309 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (10.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2023-32309? CVE-2023-32309 is a high-severity path traversal vulnerability in pymdown-extensions (pip), affecting versions >= 1.5, < 10.0. It is fixed in 10.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2023-32309? CVE-2023-32309 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of pymdown-extensions are affected by CVE-2023-32309? pymdown-extensions (pip) versions >= 1.5, < 10.0 is affected.
4. Is there a fix for CVE-2023-32309? Yes. CVE-2023-32309 is fixed in 10.0. Upgrade to this version or later.
5. Is CVE-2023-32309 exploitable, and should I be worried? Whether CVE-2023-32309 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2023-32309 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2023-32309? Upgrade pymdown-extensions to 10.0 or later.