Cyber Resilience

CVE-2020-17496

Vbulletin 5.5.4 – 5.6.2

CISA KEVActive ExploitationEUVD ExploitedPublic PoC
Published
12 August 2020
Modified
07 November 2025
KEV Added
03 November 2021
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.88 99.7th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2020-17496 is a critical-severity Injection (CWE-74) vulnerability in Vbulletin Vbulletin. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

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 5.5.4 through 5.6.2 contain a remote command execution vulnerability that stems from insufficient handling of crafted subWidgets data supplied to the ajax/render/widget_tabbedcontainer_tab_panel endpoint. The flaw is an incomplete remediation of the earlier CVE-2019-16759 issue and is tracked under CWE-74. It received a CVSS 3.1 base score of 9.8, reflecting network-accessible attack vectors that require no authentication or user interaction.

An unauthenticated remote attacker can submit a malicious request containing manipulated subWidgets parameters to execute arbitrary operating-system commands on the underlying server, resulting in full confidentiality, integrity, and availability impact. Public exploit details demonstrate that the same widget-tab rendering path used in prior attacks remains reachable after the partial patch.

The official vBulletin security announcement addresses the issue in later releases and urges administrators to apply the vendor-supplied updates for versions 5.6.0 and above. Independent analysis of the patch confirms that the widget data deserialization logic was not fully hardened, allowing continued exploitation until the corrected code is deployed.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

vBulletin 5.5.4 through 5.6.2 allows remote command execution via crafted subWidgets data in an ajax/render/widget_tabbedcontainer_tab_panel request. NOTE: this issue exists because of an incomplete fix for CVE-2019-16759.

CWE(s)
KEV Date Added
03 November 2021

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.
T1221 Template Injection Stealth
Adversaries may create or modify references in user document templates to conceal malicious code or force authentication attempts.
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
T1674 Input Injection Execution
Adversaries may simulate keystrokes on a victim’s computer by various means to perform any type of action on behalf of the user, such as launching the command interpreter using keyboard shortcuts, typing an inline script to be executed,…
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-20281Shared CWE-74both on KEV
CVE-2019-2725Shared CWE-74both on KEV
CVE-2023-22527Shared CWE-74both on KEV
CVE-2020-8468Shared CWE-74both on KEV
CVE-2019-11581Shared CWE-74both on KEV
CVE-2019-17558Shared CWE-74both on KEV
CVE-2025-20337Shared CWE-74both on KEV
CVE-2013-2251Shared CWE-74both on KEV
CVE-2022-27924Shared CWE-74both on KEV
CVE-2022-35914Shared CWE-74both on KEV

Affected Assets

vbulletin
vbulletin
5.5.4 — 5.6.2

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)
  • V1.2.1
  • V1.2.3
  • V1.2.5
  • V1.2.8

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-74

Developer assessments and testing (including injection-focused techniques) identify improper neutralization of special elements, and the verifiable flaw remediation corrects them pre-deployment.

addresses: CWE-74

Identifies indicators of injection attacks (command, SQL, LDAP, etc.) via anomaly and attack monitoring.

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 input validation and output encoding that prevent injection flaws.

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.

finds

Security testing in development catches injection vulnerabilities before release.

A.8.15 Logging partial match
finds

Logging supports detection of injection attempts but does not prevent the weakness.

finds

Monitoring activities can identify active injection attacks after they occur.

prevents

Secure development life cycle mandates input validation and output encoding that directly prevent injection flaws.

prevents

Application security requirements explicitly call for controls against injection attacks in software design.

prevents

Secure architecture principles reduce injection surfaces but do not prescribe specific neutralization techniques.

References