Cyber Resilience

CVE-2024-21499

Greenpau Caddy-Security

Published
17 February 2024
Modified
17 June 2026
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS Score 0.0050 40th percentile
Risk Priority 37 floored blend · peak EPSS

Summary

CVE-2024-21499 is a medium-severity Improper Neutralization of HTTP Headers for Scripting Syntax (CWE-644) vulnerability in Greenpau Caddy-Security. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked at the 40th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

All versions of the package github.com/greenpau/caddy-security are vulnerable to HTTP Header Injection via the X-Forwarded-Proto header due to redirecting to the injected protocol.Exploiting this vulnerability could lead to bypass of security mechanisms or confusion in handling TLS.

CWE(s)
CWE-644CWE-116

Related Threats

MITRE ATT&CK Enterprise Techniques

T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-21493Same product: Greenpau Caddy-Security
CVE-2024-21494Same product: Greenpau Caddy-Security
CVE-2024-21495Same product: Greenpau Caddy-Security
CVE-2024-21497Same product: Greenpau Caddy-Security
CVE-2023-35894Shared CWE-116, CWE-644
CVE-2024-10006Shared CWE-116, CWE-644
CVE-2023-47143Shared CWE-116, CWE-644
CVE-2023-26289Shared CWE-116, CWE-644
CVE-2024-39736Shared CWE-116, CWE-644
CVE-2024-47549Shared CWE-116, CWE-644

Affected Assets

greenpau
caddy-security
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.2.1
  • V1.2.3
  • V4.2.3

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation directly requires checking/neutralizing untrusted data such as HTTP headers before they reach browser components.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require proper output encoding and header sanitization to prevent scripting injection.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.28 Secure coding mostly match
prevents

Secure coding standards explicitly require correct output encoding and escaping to preserve message structure.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing catches header-injection issues before release, covering most of the weakness.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and output encoding that directly prevents header-injection flaws.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for neutralizing untrusted data in HTTP headers.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles reduce injection surfaces but do not prescribe header-specific controls.

References