CVE-2017-8923
Description
An integer overflow vulnerability in PHP can lead to a buffer overflow when constructing extremely long strings with the ".=" operator. In unusual circumstances, this could be used by an attacker to cause an application to crash or possibly have other consequences.
Statement
This issue is only practical to exploit on 32-bit systems, and then only when the memory limit is raised from its default to a value larger than 2 GiB. The default settings make exploitation impossible. For these reasons, PHP upstream developers do not consider this to be a security issue. Red Hat Software Collections and Red Hat Enterprise Linux 7 and later only distribute PHP built for 64-bit systems.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 9.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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