CVE-2021-46823 : Security Advisory and Response
Learn about CVE-2021-46823, a Python-ldap vulnerability that can be exploited by sending malicious regex input, leading to a denial of service condition. Take immediate action by updating to version 3.4.0 or later.
Python-ldap before 3.4.0 is vulnerable to a denial of service due to a regular expression denial of service (ReDoS) flaw in the LDAP schema parser.
Understanding CVE-2021-46823
What is CVE-2021-46823?
Python-ldap before 3.4.0 is susceptible to a denial of service when ldap.schema is utilized for untrusted schema definitions, allowing a remote authenticated attacker to trigger a denial of service.
The Impact of CVE-2021-46823
The vulnerability can be exploited by sending crafted regex input, leading to a denial of service condition.
Technical Details of CVE-2021-46823
Vulnerability Description
- Vulnerability Type: Regular Expression Denial of Service (ReDoS)
- Affects the LDAP schema parser in python-ldap before version 3.4.0
Affected Systems and Versions
- Affected Version: python-ldap versions before 3.4.0
Exploitation Mechanism
- Remote authenticated attackers can exploit the LDAP schema parser by sending malicious regex input.
Mitigation and Prevention
Immediate Steps to Take
- Update python-ldap to version 3.4.0 or later to mitigate the vulnerability
Long-Term Security Practices
- Regularly review and update LDAP schema definitions
- Implement regex input validation to prevent ReDoS attacks
- Monitor and restrict access to LDAP services
- Employ network segmentation to contain potential attacks
Patching and Updates
- Apply patches provided by the python-ldap project to address the vulnerability