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CVE Record

CVE-2019-14243: headerv2.go in mastercactapus proxyprotocol before 0.0.2, as used in the mastercactapus caddy-proxyprotocol...

headerv2.go in mastercactapus proxyprotocol before 0.0.2, as used in the mastercactapus caddy-proxyprotocol plugin through 0.0.2 for Caddy, allows remote attackers to cause a denial of service (webserver panic and daemon crash) via a crafted HAProxy PROXY v2 request with truncated source/destination address data.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This flaw can let a remote client crash a Caddy web server using the affected PROXY protocol parsing code. The business impact is availability loss, not documented data theft or code execution. Public evidence names a fix in the proxyprotocol project, but exploitation status is not reported.

Executive priority

Prioritize remediation for public or revenue-critical Caddy services using this plugin. The issue is not documented as data compromise, but a repeatable crash can create customer-visible downtime.

Technical view

CVE-2019-14243 affects headerv2.go in mastercactapus proxyprotocol before 0.0.2, used by mastercactapus caddy-proxyprotocol. Truncated source or destination address data in an HAProxy PROXY v2 request can trigger a panic and daemon crash. No CVSS, CWE, or KEV listing is provided.

Likely exposure

Exposure is most likely on Caddy deployments using mastercactapus caddy-proxyprotocol or mastercactapus proxyprotocol before 0.0.2, especially where PROXY protocol traffic can reach the service from untrusted networks.

Exploitation context

The CVE describes remote denial of service, but the provided sources do not show confirmed active exploitation or public weaponization. KEV is false. Treat internet-reachable affected deployments as availability-risk systems until verified.

Researcher notes

The evidence is narrow but consistent: affected parsing code mishandles truncated PROXY v2 address data and can panic. Version and plugin mapping should be verified locally because the CVE identifies the library fix and the plugin usage separately.

Mitigation direction

  • Inventory Caddy builds using mastercactapus caddy-proxyprotocol or mastercactapus proxyprotocol.
  • Upgrade mastercactapus proxyprotocol to v0.0.2 or later where applicable.
  • Check caddy-proxyprotocol project guidance before assuming plugin-level remediation is complete.
  • Restrict PROXY protocol listeners to trusted load balancers or internal networks.
  • Monitor affected services for panic, crash, or restart patterns.

Validation and detection

  • Review dependency manifests and build artifacts for mastercactapus proxyprotocol versions before 0.0.2.
  • Confirm whether Caddy is built with the mastercactapus caddy-proxyprotocol plugin.
  • Verify PROXY protocol endpoints are not directly reachable by untrusted clients.
  • In controlled testing, confirm malformed PROXY v2 input no longer crashes the service.
  • Review webserver and supervisor logs for prior unexplained Caddy daemon crashes.
Prepared
Confidence
medium
Sources
7

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.

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CVE-2019-14243 mapping review

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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
7Source 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

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