CVE-2019-16786 Explained : Impact and Mitigation
Learn about CVE-2019-16786, a high severity vulnerability in Waitress software versions <= 1.3.1, allowing HTTP request smuggling. Find mitigation steps and update recommendations here.
In versions prior to 1.3.1, the Waitress software had a vulnerability related to parsing the Transfer-Encoding header, potentially leading to HTTP request smuggling.
Understanding CVE-2019-16786
This CVE involves an issue in the Waitress software that could allow a single request to be treated as multiple requests due to incorrect handling of the Transfer-Encoding header.
What is CVE-2019-16786?
Waitress versions before 1.3.1 incorrectly parsed the Transfer-Encoding header, leading to potential HTTP request smuggling. This vulnerability could be exploited to manipulate the size of the HTTP message body.
The Impact of CVE-2019-16786
The vulnerability had a CVSS base score of 7.1, indicating a high severity issue with significant confidentiality impact and potential for HTTP request manipulation.
Technical Details of CVE-2019-16786
This section provides more in-depth technical details about the vulnerability.
Vulnerability Description
Waitress versions <= 1.3.1 incorrectly processed the Transfer-Encoding header, potentially allowing for HTTP request smuggling attacks.
Affected Systems and Versions
- Product: Waitress
- Vendor: Pylons
- Versions Affected: <= 1.3.1
Exploitation Mechanism
The vulnerability stemmed from Waitress parsing the Transfer-Encoding header as a single string value, leading to incorrect handling of chunked encoding and reliance on the Content-Length header.
Mitigation and Prevention
To address CVE-2019-16786, users and organizations should take immediate and long-term security measures.
Immediate Steps to Take
- Update Waitress to version 1.4.0 or later to mitigate the vulnerability.
- Monitor for any unusual HTTP request behavior that could indicate exploitation.
Long-Term Security Practices
- Regularly update software components to ensure the latest security patches are applied.
- Educate developers and administrators on secure coding practices and HTTP header handling.
Patching and Updates
- Apply patches provided by the vendor promptly to address security vulnerabilities.