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CVE Record

CVE-2019-11043: Underflow in PHP-FPM can lead to RCE

In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it is possible to cause FPM module to write past allocated buffers into the space reserved for FCGI protocol data, thus opening the possibility of remote code execution.

HighCVSS 8.7Known exploitedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2019-11043 is a remote code execution flaw in PHP-FPM. In certain web server configurations, an unauthenticated internet request could cause PHP-FPM to corrupt memory and potentially run attacker-controlled code. The issue affects older PHP 7.1, 7.2, and 7.3 releases before the fixed versions named in the CVE record.

Executive priority

Treat this as a high-priority legacy web stack issue. It combines remote code execution potential, no required authentication, and known exploitation evidence. Patch or retire affected PHP-FPM deployments, starting with public web applications and vendor appliances.

Technical view

The flaw is an underflow/buffer overwrite condition in PHP-FPM that can write past allocated buffers into FastCGI protocol data. The CVE describes exposure only in certain FPM setups, with affected PHP branches 7.1.x before 7.1.33, 7.2.x before 7.2.24, and 7.3.x before 7.3.11.

Likely exposure

Most likely exposure is internet-facing PHP applications running PHP-FPM on affected PHP 7.1, 7.2, or 7.3 versions, especially legacy Linux distribution packages or appliances that embedded PHP-FPM before vendor fixes were applied.

Exploitation context

The source bundle marks this CVE as KEV, supporting known exploitation. A public GitHub repository is also referenced. The CVE still says exploitation depends on certain PHP-FPM configurations, so version alone is not complete proof of exploitability.

Researcher notes

The public evidence identifies affected PHP branches, memory corruption in PHP-FPM/FastCGI handling, and multiple vendor advisories. The bundle does not provide a universal affected-configuration test or complete product matrix, so validation should combine version checks, package advisory mapping, and configuration review.

Mitigation direction

  • Upgrade PHP to a fixed vendor package or later supported release.
  • Prioritize internet-facing PHP-FPM systems and appliances first.
  • Apply relevant Linux distribution advisories for Ubuntu, Debian, Fedora, Red Hat, and openSUSE.
  • Check product-specific advisories from affected vendors such as F5, NetApp, and Synology.
  • If immediate patching is blocked, review vendor guidance for configuration mitigations.

Validation and detection

  • Inventory internet-facing hosts running PHP-FPM.
  • Confirm PHP versions are not below 7.1.33, 7.2.24, or 7.3.11.
  • Map installed packages to vendor advisory fixed builds.
  • Review web server and PHP-FPM configurations for the affected setup described by vendors.
  • Check exposure management tools for KEV status and remediation SLA tracking.
Prepared
Confidence
high
Sources
11

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

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-120: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2019-11043 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.7 (3.1)
Known Exploited
Yes
Published

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

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.

1CVSS vectors
0Timeline events
0ADP providers
25Source links

CISA KEV status

Status
Known exploited
Source
CISA / ADP
Date added
Not provided

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.7CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N2.25.8Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

8.7High
CVSS 3.1 vector shape for CVE-2019-11043Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
PHPPHP7.1.x, 7.2.x, 7.3.xListed
Weakness

CWE details

CWE-120

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-120 · source CWE mapping

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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