CVE-2017-6004 : Exploit Details and Defense Strategies
CVE-2017-6004 exposes a vulnerability in PCRE's compile_bracket_matchingpath function, allowing remote attackers to trigger a denial of service. Learn about the impact, affected systems, exploitation, and mitigation steps.
PCRE, which stands for Perl-Compatible Regular Expressions, has a vulnerability in the compile_bracket_matchingpath function in its pcre_jit_compile.c file. This vulnerability affects versions of PCRE up to 8.x before revision 1680, including the bundled version in PHP 7.1.1. Attackers can exploit this vulnerability remotely, leading to a denial of service by causing an out-of-bounds read and application crash.
Understanding CVE-2017-6004
This CVE identifies a specific vulnerability in PCRE that can be exploited to execute a denial of service attack remotely.
What is CVE-2017-6004?
The compile_bracket_matchingpath function in pcre_jit_compile.c in PCRE through 8.x before revision 1680 allows remote attackers to cause a denial of service via a crafted regular expression.
The Impact of CVE-2017-6004
The vulnerability can be exploited remotely, resulting in a denial of service by triggering an out-of-bounds read and causing the application to crash.
Technical Details of CVE-2017-6004
This section provides more technical insights into the vulnerability.
Vulnerability Description
The vulnerability lies in the compile_bracket_matchingpath function in pcre_jit_compile.c in PCRE versions up to 8.x before revision 1680, allowing remote attackers to execute a denial of service attack.
Affected Systems and Versions
- PCRE versions up to 8.x before revision 1680
- PHP 7.1.1 (bundled version)
Exploitation Mechanism
Attackers can exploit this vulnerability remotely by using a manipulated regular expression, leading to an out-of-bounds read and application crash.
Mitigation and Prevention
Protecting systems from CVE-2017-6004 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Apply patches provided by the vendor to mitigate the vulnerability.
- Monitor security advisories for updates and apply them promptly.
Long-Term Security Practices
- Regularly update software and libraries to the latest versions.
- Implement network security measures to detect and prevent remote attacks.
Patching and Updates
- Check for patches and updates from PCRE, PHP, and other relevant vendors to address the vulnerability.