Cyber Resilience

CVE-2025-48827

Vbulletin 5.0.0 – 5.7.5

Public PoCHigh EPSS
Published
27 May 2025
Modified
17 June 2026
CVSS Score v3.1 10.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.77 99.5th percentile
Risk Priority 100 floored blend · peak EPSS

Summary

CVE-2025-48827 is a critical-severity Improper Protection of Alternate Path (CWE-424) vulnerability in Vbulletin Vbulletin. Its CVSS base score is 10.0 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

vBulletin versions 5.0.0 through 5.7.5 and 6.0.0 through 6.0.3 contain an access-control flaw that permits unauthenticated callers to reach protected API controller methods when the software runs on PHP 8.1 or later. The issue is triggered by supplying a protected method name directly to the /api.php endpoint, bypassing the normal authorization checks that the application relies on for its internal controllers.

An unauthenticated remote attacker can therefore invoke arbitrary protected functionality, resulting in full compromise of the vBulletin installation. The vulnerability carries a CVSS 3.1 score of 10.0 with network attack vector, no required credentials or user interaction, and complete impact on confidentiality, integrity, and availability under changed scope.

The flaw was observed being exploited in the wild during May 2025. Its EPSS score has reached a peak of 0.8108 and currently stands at 0.7763, indicating sustained attacker interest after public disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

vBulletin 5.0.0 through 5.7.5 and 6.0.0 through 6.0.3 allows unauthenticated users to invoke protected API controllers' methods when running on PHP 8.1 or later, as demonstrated by the /api.php?method=protectedMethod pattern, as exploited in the wild in May 2025.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

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.
T1083 File and Directory Discovery Discovery
Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-48828Same product: Vbulletin Vbulletin
CVE-2016-6195Same product: Vbulletin Vbulletin
CVE-2020-12720Same product: Vbulletin Vbulletin
CVE-2023-25135Same product: Vbulletin Vbulletin
CVE-2023-39777Same product: Vbulletin Vbulletin
CVE-2020-17496Same product: Vbulletin Vbulletin
CVE-2019-16759Same product: Vbulletin Vbulletin
CVE-2025-46171Same product: Vbulletin Vbulletin
CVE-2023-20272Shared CWE-424
CVE-2025-49162Shared CWE-424

Affected Assets

vbulletin
vbulletin
5.0.0 — 5.7.5 · 6.0.0 — 6.0.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Requiring access-control decisions to be applied to each request ensures no alternate path can bypass authorization checks.

A reference monitor that is always invoked by definition covers every possible path, eliminating the root cause of unprotected alternate paths.

Enforcing approved authorizations for every logical access request structurally blocks unprotected alternate paths to restricted resources.

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.AA-05 mostly match
prevents

Enforcing and reviewing authorizations across all access paths directly prevents alternate-path bypasses.

PR.IR-01 partial match
prevents

Logical segmentation and unauthorized-access protections reduce the attack surface of unprotected alternate paths.

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.

prevents

Privileged access rights must be enforced on every possible route to privileged functions.

finds

Security testing can discover unprotected alternate paths before release.

prevents

Information access restriction mechanisms must close all alternate paths to restricted data or functions.

prevents

Access control policy directly requires protection of all entry points to restricted functionality.

prevents

Managing access rights must cover every alternate path that could bypass intended restrictions.

mitigates

Network security can limit some alternate paths but is not the primary control for application-level path protection.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 9 (1 rule)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-424
RHEL 9 (1 rule)
  • V-258078 RHEL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-424
Ubuntu 22.04 (1 rule)
  • V-260529 Ubuntu 22.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements. prevents CWE-424
Ubuntu 24.04 (1 rule)
  • V-270708 Ubuntu 24.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements. prevents CWE-424

References