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CVE Record

CVE-2015-9253: 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.

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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2015-9253 is an availability issue in older PHP-FPM versions. Under specific conditions, PHP-FPM can repeatedly restart a child process, driving the master process to 100% CPU and producing large error logs that consume disk. The source description notes this was demonstrated in a shared-hosting setting.

Executive priority

Prioritize remediation for shared-hosting or multi-tenant PHP-FPM fleets because one tenant may affect service availability. For isolated, fully patched, or non-PHP-FPM systems, urgency is lower. The main business risk is outage or degraded hosting capacity, not confirmed data theft.

Technical view

Affected PHP versions are before 7.1.20, 7.2.8, and 7.3.0alpha3. The issue involves php-fpm, program execution functions such as exec-family calls, and a non-blocking STDIN stream. The failure mode is an endless child restart loop causing CPU exhaustion and log growth.

Likely exposure

Exposure is most likely where older PHP-FPM versions run untrusted or tenant-controlled PHP code, especially shared hosting. Single-tenant applications are still exposed if vulnerable PHP-FPM versions and triggering code paths exist. The bundle does not identify affected downstream products beyond PHP versions.

Exploitation context

The source bundle does not show CISA KEV listing or current active exploitation. It does state the behavior was demonstrated by a customer of a shared-hosting facility. Treat exploitation evidence as limited to that public description.

Researcher notes

The public record is sparse: no CVSS, CWE, or KEV evidence is provided in the bundle. The strongest technical indicators are the PHP version boundaries, php-fpm restart-loop behavior, and upstream references. Avoid overstating scope beyond PHP-FPM and the listed fixed versions.

Mitigation direction

  • Upgrade PHP to 7.1.20, 7.2.8, 7.3.0alpha3, or later supported releases.
  • Apply vendor distribution updates, including relevant Ubuntu security updates where applicable.
  • Prioritize shared-hosting and multi-tenant PHP-FPM environments.
  • Review vendor guidance before applying operational workarounds.
  • Monitor php-fpm CPU saturation and abnormal error-log growth.

Validation and detection

  • Inventory PHP-FPM versions across internet-facing and shared-hosting systems.
  • Confirm package versions include the PHP upstream fix or vendor backport.
  • Check whether applications use program execution functions under PHP-FPM.
  • Review php-fpm logs for restart loops and rapid error-log growth.
  • Verify monitoring alerts on CPU saturation and disk usage.
Prepared
Confidence
medium
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
9Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

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