CVE-2019-9516 Explained : Impact and Mitigation

Certain HTTP/2 implementations have a vulnerability that can result in a header leak, potentially causing a denial of service.

Understanding CVE-2019-9516

Some HTTP/2 implementations are vulnerable to a header leak, potentially leading to a denial of service due to excessive memory consumption.

What is CVE-2019-9516?

Vulnerability in certain HTTP/2 implementations causing a header leak
Attacker sends headers with zero-length name and value, leading to memory allocation
Excessive memory consumption due to headers kept alive until session termination

The Impact of CVE-2019-9516

CVSS Score: 7.5 (High)
Attack Vector: Network
Availability Impact: High
Attack Complexity: Low
No impact on Confidentiality or Integrity

Technical Details of CVE-2019-9516

Vulnerability Description

HTTP/2 vulnerability causing a header leak
Attackers exploit by sending headers with zero-length name and value
Memory allocation for headers persists until session termination

Affected Systems and Versions

No specific products or versions mentioned

Exploitation Mechanism

Attacker sends headers with zero-length name and value
Headers may be Huffman encoded into one-byte or larger headers
Memory allocated for headers remains until the session ends

Mitigation and Prevention

Immediate Steps to Take

Implement patches provided by relevant vendors
Monitor memory consumption for unusual spikes
Consider disabling HTTP/2 if not essential

Long-Term Security Practices

Regularly update software and systems
Conduct security audits to identify vulnerabilities
Educate staff on secure coding practices

Patching and Updates

Check vendor advisories for patches and updates
Apply security updates promptly to mitigate risks