CVE-2023-40587 Pyramid static view path traversal up one directory
Attackers can read index.html files one directory above static views in Pyramid when using specific Python versions and configurations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2023-40587?
CVE-2023-40587 is a medium-severity path traversal vulnerability in Fedoraproject Fedora, published on 25 Aug 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Pyramid is an open source Python web framework. A path traversal vulnerability in Pyramid versions 2.0.0 and 2.0.1 impacts users of Python 3.11 that are using a Pyramid static view with a full filesystem path and have a `index.html` file that is located exactly one directory above the location of the static view's file system path. No further path traversal exists, and the only file that could be disclosed accidentally is `index.html`. Pyramid version 2.0.2 rejects any path that contains a null-byte out of caution. While valid in directory/file names, we would strongly consider it a mistake to use null-bytes in naming files/directories. Secondly, Python 3.11, and 3.12 has fixed the underlying issue in `os.path.normpath` to no longer truncate on the first `0x00` found, returning the behavior to pre-3.11 Python, un an as of yet unreleased version. Fixes will be available in:Python 3.12.0rc2 and 3.11.5. Some workarounds are available. Use a version of Python 3 that is not affected, downgrade to Python 3.10 series temporarily, or wait until Python 3.11.5 is released and upgrade to the latest version of Python 3.11 series.
Weakness: CWE-22
Which versions are affected by CVE-2023-40587?
3 open source packages ship an affected version, including pyramid. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
pyramid PyPI | From 2.0.0 | 2.0.2 |
pyramid PyPI | From 2.0.0 | 2.0.2 |
pyramid PyPI | From 2.0.0 | 2.0.2 |
Products include Agendaless Pyramid, Fedoraproject Fedora.
How do I fix CVE-2023-40587?
Upgrade pyramid to 2.0.2 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2023-40587 being exploited?
There is no known exploitation of CVE-2023-40587 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2023-40587, GHSA-j8g2-6fc7-q8f8, PYSEC-2026-1840, UBUNTU-CVE-2023-40587.