CVE-2019-20433 : Security Advisory and Response
Learn about CVE-2019-20433, a buffer over-read vulnerability in GNU Aspell versions prior to 0.60.8. Find out the impact, affected systems, exploitation mechanism, and mitigation steps.
In versions of GNU Aspell prior to 0.60.8, a buffer over-read vulnerability exists in the libaspell.a library when encountering a string ending with a single '\0' byte with the encoding set to ucs-2 or ucs-4 outside of the application, as demonstrated by the ASPELL_CONF environment variable.
Understanding CVE-2019-20433
This CVE involves a buffer over-read vulnerability in GNU Aspell prior to version 0.60.8.
What is CVE-2019-20433?
This CVE refers to a specific security vulnerability in the libaspell.a library of GNU Aspell versions before 0.60.8, where a buffer over-read can occur under certain conditions.
The Impact of CVE-2019-20433
The vulnerability can potentially lead to information disclosure or denial of service if exploited by malicious actors.
Technical Details of CVE-2019-20433
This section provides more technical insights into the CVE.
Vulnerability Description
The vulnerability arises from a buffer over-read issue in the libaspell.a library when processing strings with specific encodings outside of the application context.
Affected Systems and Versions
- Affected versions: GNU Aspell versions prior to 0.60.8
- Systems using ucs-2 or ucs-4 encoding outside of the application
Exploitation Mechanism
The vulnerability is triggered when encountering a string that ends with a single '\0' byte with the encoding set to ucs-2 or ucs-4 outside of the application, such as through the ASPELL_CONF environment variable.
Mitigation and Prevention
Protective measures to address CVE-2019-20433.
Immediate Steps to Take
- Update GNU Aspell to version 0.60.8 or later to mitigate the vulnerability.
- Avoid using ucs-2 or ucs-4 encoding outside of the application where possible.
Long-Term Security Practices
- Regularly monitor for security advisories and updates related to GNU Aspell.
- Implement secure coding practices to prevent buffer over-read vulnerabilities.
Patching and Updates
- Apply patches and updates provided by GNU Aspell to address security issues promptly.