CVE-2019-11467 : Vulnerability Insights and Analysis

Couchbase Server versions 4.6.3 and 5.5.0 were affected by a vulnerability related to secondary indexing, leading to buffer overruns and crashes in the indexer service. Versions 5.1.2 and 5.5.2 addressed this issue by dynamically growing the buffer as needed.

Understanding CVE-2019-11467

This CVE entry describes a vulnerability in Couchbase Server versions 4.6.3 and 5.5.0 that could result in crashes and restarts of the indexer service.

What is CVE-2019-11467?

In Couchbase Server versions 4.6.3 and 5.5.0, the secondary indexing feature used collatejson to encode entries for indexing. However, encoding specific characters like \t, <, > could cause buffer overruns, leading to crashes and restarts of the indexer service.

The Impact of CVE-2019-11467

The vulnerability could potentially disrupt the availability of the Couchbase Server by causing crashes and restarts of the indexer service.

Technical Details of CVE-2019-11467

This section provides more technical insights into the vulnerability.

Vulnerability Description

The issue stemmed from the encoding process of index entries using collatejson, which could result in buffer overruns due to specific characters, leading to service disruptions.

Affected Systems and Versions

Couchbase Server versions 4.6.3 and 5.5.0

Exploitation Mechanism

By including certain characters like \t, <, > in index entries, the encoded string would exceed the expected size, causing crashes and restarts.

Mitigation and Prevention

To address CVE-2019-11467, follow these mitigation steps:

Immediate Steps to Take

Upgrade to Couchbase Server versions 5.1.2 or 5.5.2
Monitor for any unusual crashes or restarts in the indexer service

Long-Term Security Practices

Regularly update Couchbase Server to the latest versions
Implement input validation mechanisms to prevent buffer overflows

Patching and Updates

Apply patches provided by Couchbase to ensure the buffer dynamically grows as needed for any input.