PHP php_pcre_replace_impl Function Out-of-Bounds Memory Access Denial of Service Vulnerability [CVE-2017-9118]
CVE Number = CVE-2017-9118
A vulnerability in PHP could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.
The vulnerability is due to an out-of-bounds memory access in the php_pcre_replace_impl function, as defined in the source code file php_pcre.c, that could cause the affected software to crash. An attacker could exploit the vulnerability by calling preg_replace() with arguments that submit malicious input to the affected software. A successful exploit could allow the attacker to cause the affected software to crash, resulting in a DoS condition.
Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available.
PHP has confirmed the vulnerability; however, software updates are not available.
-
To exploit this vulnerability, the attacker must send a malicious request to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.
-
Administrators are advised to contact the vendor regarding future updates and releases.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
Administrators are advised to monitor affected systems.
-
PHP has confirmed the vulnerability in bug #74604 at the following link: Out of bounds in php_pcre_replace_impl
-
At the time this alert was first published, software updates were unavailable.
Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.