CVE-2019-18801 Explained : Impact and Mitigation

A vulnerability found in version 1.12.0 of Envoy allows untrusted remote clients to send HTTP/2 requests that can write outside designated buffers, potentially leading to heap corruption and bypassing access controls.

Understanding CVE-2019-18801

This CVE involves a security issue in Envoy version 1.12.0 that can be exploited by remote attackers.

What is CVE-2019-18801?

In Envoy 1.12.0, untrusted remote clients can send HTTP/2 requests that write outside request buffers when the upstream is HTTP/1.
This vulnerability can corrupt neighboring heap contents, leading to a query-of-death scenario and bypassing access control mechanisms.
Attackers can manipulate requests from other users in close proximity both temporally and spatially.

The Impact of CVE-2019-18801

Allows attackers to write to the heap outside of designated buffers, potentially leading to heap corruption.
Enables bypassing of Envoy's access control mechanisms like path-based routing.
Facilitates manipulation of requests from other users in close proximity.

Technical Details of CVE-2019-18801

This section provides detailed technical information about the vulnerability.

Vulnerability Description

Untrusted remote clients can exploit the vulnerability in Envoy 1.12.0 to write outside designated request buffers.

Affected Systems and Versions

Product: Envoy
Vendor: N/A
Version: 1.12.0

Exploitation Mechanism

Attackers can send HTTP/2 requests to corrupt neighboring heap contents and bypass access controls.

Mitigation and Prevention

Protecting systems from CVE-2019-18801 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Envoy to a patched version that addresses the vulnerability.
Monitor and restrict network access to vulnerable systems.

Long-Term Security Practices

Regularly update and patch software to prevent known vulnerabilities.
Implement network segmentation to limit the impact of potential attacks.

Patching and Updates

Apply security patches provided by Envoy to fix the vulnerability.