CVE-2019-19906 Explained : Impact and Mitigation
Learn about CVE-2019-19906, an unauthenticated remote denial-of-service vulnerability in cyrus-sasl 2.1.27 triggered by a malformed LDAP packet. Find out the impact, affected systems, exploitation mechanism, and mitigation steps.
An unauthenticated remote denial-of-service vulnerability is found in cyrus-sasl (also known as Cyrus SASL) version 2.1.27. This vulnerability is triggered by a malformed LDAP packet and results in an out-of-bounds write. The crash in OpenLDAP is caused by an off-by-one error in the _sasl_add_string function located in common.c of cyrus-sasl.
Understanding CVE-2019-19906
This CVE refers to a specific vulnerability in cyrus-sasl version 2.1.27 that can lead to a denial-of-service attack.
What is CVE-2019-19906?
CVE-2019-19906 is an unauthenticated remote denial-of-service vulnerability in cyrus-sasl 2.1.27 due to an out-of-bounds write triggered by a malformed LDAP packet.
The Impact of CVE-2019-19906
This vulnerability can be exploited remotely by an attacker to cause a denial-of-service condition in systems running the affected version of cyrus-sasl.
Technical Details of CVE-2019-19906
This section provides more in-depth technical information about the vulnerability.
Vulnerability Description
The vulnerability in cyrus-sasl 2.1.27 leads to an out-of-bounds write in OpenLDAP via a malformed LDAP packet, ultimately caused by an off-by-one error in _sasl_add_string in common.c.
Affected Systems and Versions
- Product: Not applicable
- Vendor: Not applicable
- Version: 2.1.27
Exploitation Mechanism
The vulnerability is exploited by sending a specially crafted LDAP packet to the target system, triggering the out-of-bounds write and resulting in a denial-of-service condition.
Mitigation and Prevention
It is crucial to take immediate steps to address and prevent the exploitation of this vulnerability.
Immediate Steps to Take
- Update cyrus-sasl to a patched version that addresses the vulnerability.
- Implement network-level protections to filter out potentially malicious LDAP packets.
Long-Term Security Practices
- Regularly update and patch software to protect against known vulnerabilities.
- Conduct security assessments and audits to identify and mitigate potential risks.
Patching and Updates
Ensure that all systems running cyrus-sasl are updated with the latest security patches to prevent exploitation of this vulnerability.