Cyber Resilience

CVE-2023-49316

DoS in Phpseclib 3.0.0 – 3.0.34

DoS
Published
27 November 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0078 53th percentile
Risk Priority 59 floored blend · peak EPSS

Summary

CVE-2023-49316 is a high-severity Excessive Iteration (CWE-834) vulnerability in Phpseclib Phpseclib. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked in the top 47% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

In Math/BinaryField.php in phpseclib 3 before 3.0.34, excessively large degrees can lead to a denial of service.

CWE(s)
CWE-834

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-27560Same product: Phpseclib Phpseclib
CVE-2026-55599Same product: Phpseclib Phpseclib
CVE-2026-40194Same product: Phpseclib Phpseclib
CVE-2026-32935Same product: Phpseclib Phpseclib
CVE-2023-52892Same product: Phpseclib Phpseclib
CVE-2024-27355Same product: Phpseclib Phpseclib
CVE-2024-27354Same product: Phpseclib Phpseclib
CVE-2025-55181Shared CWE-834
CVE-2026-64641Shared CWE-834
CVE-2026-41313Shared CWE-834

Affected Assets

phpseclib
phpseclib
3.0.0 — 3.0.34

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

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Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

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 prevent unbounded loops via code review, static analysis, and testing.

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.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect excessive iteration through stress and fuzz testing.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle requires input validation and loop bounds, directly limiting excessive iteration.

A.8.26 Application security requirements partial match
prevents

Application security requirements include resource-consumption limits that prevent unbounded loops.

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

Secure architecture principles mandate defensive coding patterns such as loop termination checks.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unbounded loops and require explicit iteration limits.

References