CVE-2020-1983 : Security Advisory and Response

A detailed overview of CVE-2020-1983, a use after free vulnerability in libslirp, version 4.2.0, allowing crafted packets to trigger a denial of service.

Understanding CVE-2020-1983

CVE-2020-1983 is a use after free vulnerability in libslirp, specifically in the ip_reass() function in ip_input.c, affecting version 4.2.0 and earlier releases. This vulnerability could be exploited to cause a denial of service.

What is CVE-2020-1983?

A use after free vulnerability in libslirp 4.2.0 and prior releases enables specially crafted packets to induce a denial of service.

The Impact of CVE-2020-1983

The vulnerability poses a significant risk with a CVSS base score of 7.5, categorized as high severity due to its potential to impact availability.

Technical Details of CVE-2020-1983

CVE-2020-1983 focuses on a specific use after free vulnerability within the libslirp library, leading to a denial of service.

Vulnerability Description

The issue lies in the ip_reass() function in ip_input.c of libslirp 4.2.0 and prior, allowing specifically crafted packets to trigger the vulnerability.

Affected Systems and Versions

Product: libslirp
Vendor: slirp
Versions affected: 4.2.0 and below

Exploitation Mechanism

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
CVSS Score: 7.5 (High)

Mitigation and Prevention

Steps to address and safeguard systems from the CVE-2020-1983 vulnerability.

Immediate Steps to Take

Update libslirp to version 4.2.1 or a secure release
Implement network filtering to block potentially malicious packets

Long-Term Security Practices

Regular security audits and code reviews
Keep systems up-to-date with the latest security patches

Patching and Updates

Stay informed about security advisories and apply patches promptly