CVE Vulnerabilities

CVE-2015-9253

Uncontrolled Resource Consumption

Published: Feb 19, 2018 | Modified: Nov 21, 2024
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
6.8 MEDIUM
AV:N/AC:L/Au:S/C:N/I:N/A:C
RedHat/V2
RedHat/V3
7.5 MODERATE
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Ubuntu
LOW

An issue was discovered in PHP 7.3.x before 7.3.0alpha3, 7.2.x before 7.2.8, and before 7.1.20. The php-fpm master process restarts a child process in an endless loop when using program execution functions (e.g., passthru, exec, shell_exec, or system) with a non-blocking STDIN stream, causing this master process to consume 100% of the CPU, and consume disk space with a large volume of error logs, as demonstrated by an attack by a customer of a shared-hosting facility.

Weakness

The product does not properly control the allocation and maintenance of a limited resource.

Affected Software

Name Vendor Start Version End Version
Php Php * 7.1.20 (excluding)
Php Php 7.2.0 (including) 7.2.8 (excluding)
Php Php 7.3.0-alpha1 (including) 7.3.0-alpha1 (including)
Php Php 7.3.0-alpha2 (including) 7.3.0-alpha2 (including)
Php5 Ubuntu esm-infra-legacy/trusty *
Php5 Ubuntu trusty *
Php5 Ubuntu trusty/esm *
Php7.0 Ubuntu esm-infra/xenial *
Php7.0 Ubuntu upstream *
Php7.0 Ubuntu xenial *
Php7.2 Ubuntu bionic *
Php7.2 Ubuntu cosmic *
Php7.2 Ubuntu disco *
Php7.2 Ubuntu esm-infra/bionic *
Php7.2 Ubuntu upstream *

Potential Mitigations

  • Mitigation of resource exhaustion attacks requires that the target system either:

  • The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

  • The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

References