GHSA-r7r6-cc7p-4v5m
python-ldap has sanitization bypass in ldap.filter.escape_filter_chars
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
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Description
Summary
The sanitization method ldap.filter.escape_filter_chars can be tricked to skip escaping of special characters when a crafted list or dict is supplied as the assertion_value parameter, and the non-default escape_mode=1 is configured.
Details
The method ldap.filter.escape_filter_chars supports 3 different escaping modes. escape_mode=0 (default) and escape_mode=2 happen to raise exceptions when a list or dict object is supplied as the assertion_value parameter. However, escape_mode=1 happily computes without performing adequate logic to ensure a fully escaped return value.
PoC
>>> import ldap.filter
Exploitable
>>> ldap.filter.escape_filter_chars(["abc@*()/xyz"], escape_mode=1)
'abc@*()/xyz'
>>> ldap.filter.escape_filter_chars({"abc@*()/xyz": 1}, escape_mode=1)
'abc@*()/xyz'
Not exploitable
>>> ldap.filter.escape_filter_chars("abc@*()/xyz", escape_mode=1)
'abc@\\2a\\28\\29\\2fxyz'
>>> ldap.filter.escape_filter_chars(["abc@*()/xyz"], escape_mode=0)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib64/python3.12/site-packages/ldap/filter.py", line 41, in escape_filter_chars
s = assertion_value.replace('\\', r'\5c')
^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'list' object has no attribute 'replace'
>>> ldap.filter.escape_filter_chars(["abc@*()/xyz"], escape_mode=2)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib64/python3.12/site-packages/ldap/filter.py", line 36, in escape_filter_chars
r.append("\\%02x" % ord(c))
^^^^^^
TypeError: ord() expected a character, but string of length 11 found
Impact
If an application relies on the vulnerable method in the python-ldap library to escape untrusted user input, an attacker might be able to abuse the vulnerability to launch ldap injection attacks which could potentially disclose or manipulate ldap data meant to be inaccessible to them.
With Python being a dynamically typed language, and the commonly used JSON format supporting list and dict, it is to be expected that Python applications may commonly forward unchecked and potentially malicious list and dict objects to the vulnerable sanitization method.
The vulnerable escape_mode=1 configuration does not appear to be widely used.
Suggested Fix
Add a type check at the start of the ldap.filter.escape_filter_chars method to raise an exception when the supplied assertion_value parameter is not of type str.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | python-ldap | all versions | 3.4.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for python-ldap. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update python-ldap to 3.4.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-r7r6-cc7p-4v5m is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-r7r6-cc7p-4v5m is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-r7r6-cc7p-4v5m. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-r7r6-cc7p-4v5m in your dependencies?
O3 detects GHSA-r7r6-cc7p-4v5m across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.