CVE-2019-20454 : Exploit Details and Defense Strategies

A vulnerability in PCRE versions earlier than 10.34 could allow attackers to crash applications. The flaw lies in the function do_extuni_no_utf within the pcre2_jit_compile.c file.

Understanding CVE-2019-20454

This CVE identifies a specific vulnerability in PCRE versions prior to 10.34 that could be exploited by attackers to cause application crashes.

What is CVE-2019-20454?

The vulnerability arises when the pattern \X is compiled using JIT and is used to match manipulated subjects in non-UTF mode. Applications relying on PCRE for analyzing untrusted input are at risk.

The Impact of CVE-2019-20454

Attackers could exploit the vulnerability to crash applications that utilize PCRE for input analysis.

Technical Details of CVE-2019-20454

This section provides technical insights into the vulnerability.

Vulnerability Description

The vulnerability is located in the function do_extuni_no_utf within the pcre2_jit_compile.c file.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Versions: All versions earlier than 10.34 are affected.

Exploitation Mechanism

The flaw occurs when the pattern \X is compiled using JIT and is used to match manipulated subjects in non-UTF mode.

Mitigation and Prevention

Protective measures to address CVE-2019-20454.

Immediate Steps to Take

Update PCRE to version 10.34 or later to mitigate the vulnerability.
Monitor vendor advisories and apply patches promptly.

Long-Term Security Practices

Regularly update software and libraries to the latest versions.
Implement input validation mechanisms to prevent exploitation of vulnerabilities.

Patching and Updates

Apply patches provided by PCRE to address the vulnerability.