CVE-2017-17740 : What You Need to Know

OpenLDAP version 2.4.45 is vulnerable due to a specific configuration. Remote attackers can exploit this issue to cause a denial of service by triggering a slapd crash.

Understanding CVE-2017-17740

In OpenLDAP version 2.4.45, a vulnerability exists in the contrib/slapd-modules/nops/nops.c file when both the nops module and the memberof overlay are enabled.

What is CVE-2017-17740?

The vulnerability allows remote attackers to induce a denial of service, specifically a slapd crash, by exploiting a member MODDN operation. The root cause is an attempt to free a buffer allocated on the stack.

The Impact of CVE-2017-17740

The exploitation of this vulnerability can lead to a complete denial of service, affecting the availability of the OpenLDAP service.

Technical Details of CVE-2017-17740

OpenLDAP version 2.4.45 is affected by the following technical aspects:

Vulnerability Description

The issue arises in the nops module and memberof overlay interaction, causing a slapd crash.

Affected Systems and Versions

Product: OpenLDAP
Version: 2.4.45

Exploitation Mechanism

Remote attackers can trigger a slapd crash by exploiting a member MODDN operation.

Mitigation and Prevention

To address CVE-2017-17740, consider the following steps:

Immediate Steps to Take

Disable the nops module and memberof overlay if not essential.
Monitor for any unusual activity or crashes in the OpenLDAP service.

Long-Term Security Practices

Regularly update OpenLDAP to the latest version to patch known vulnerabilities.

Patching and Updates

Apply patches provided by OpenLDAP to mitigate the vulnerability and enhance system security.