Security Resilience

CVE-2023-2437

Auth Bypass in Userproplugin Userpro ≤ 5.1.1

Public PoCAuth Bypass
Published
22 November 2023
Modified
08 April 2026
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 0.067 94th percentile
Risk Priority 97 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-2437 is a critical-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Userproplugin Userpro. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV 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.

The UserPro plugin for WordPress, a commercial user-profile and social-login component sold through Codecanyon, contains an authentication-bypass flaw in all versions through 5.1.1. The root cause is insufficient verification of the identity supplied during Facebook-login handling, which maps directly to CWE-287 and CWE-288. The issue carries a CVSS 3.1 score of 9.8.

Unauthenticated attackers who possess a target user’s email address can exploit the flaw to obtain a valid session as that user, including site administrators. The advisory notes that the required email can be obtained by chaining CVE-2023-2448 and CVE-2023-2446, after which the attacker completes the Facebook login flow without further proof of identity. Exploitation requires only network access and no user interaction.

EPSS for the CVE currently stands at 0.7549 with a recorded peak of 0.7679, indicating sustained and moderately high exploitation interest since disclosure. No public evidence of widespread in-the-wild attacks has been reported in the supplied references.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

The UserPro plugin for WordPress is vulnerable to authentication bypass in versions up to, and including, 5.1.1. This is due to insufficient verification on the user being supplied during a Facebook login through the plugin. This makes it possible for…

more

unauthenticated attackers to log in as any existing user on the site, such as an administrator, if they have access to the email. An attacker can leverage CVE-2023-2448 and CVE-2023-2446 to get the user's email address to successfully exploit this vulnerability.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001 Data Obfuscation Command And Control
Adversaries may obfuscate command and control traffic to make it more difficult to detect.
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
T1003.002 Security Account Manager Credential Access
Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored.
T1018 Remote System Discovery Discovery
Adversaries may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system.
T1027.006 HTML Smuggling Stealth
Adversaries may smuggle data and files past content filters by hiding malicious payloads inside of seemingly benign HTML files.
T1027.009 Embedded Payloads Stealth
Adversaries may embed payloads within other files to conceal malicious content from defenses.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-2446Same product: Userproplugin Userpro
CVE-2024-0701Same product: Userproplugin Userpro
CVE-2023-2497Same product: Userproplugin Userpro
CVE-2023-6009Same product: Userproplugin Userpro
CVE-2023-2448Same product: Userproplugin Userpro
CVE-2024-35700Same product: Userproplugin Userpro
CVE-2023-2438Same product: Userproplugin Userpro
CVE-2023-2447Same product: Userproplugin Userpro
CVE-2023-6007Same product: Userproplugin Userpro
CVE-2023-2439Same product: Userproplugin Userpro

Affected Assets

userproplugin
userpro
≤ 5.1.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.3
  • V6.6.1
  • V12.1.3

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-287 CWE-288

Detects unauthorized successful logons resulting from improper authentication implementations.

addresses: CWE-287 CWE-288

Requires adaptive authentication under specific conditions, directly strengthening authentication mechanisms against improper or insufficient authentication.

addresses: CWE-287 CWE-288

Identity providers centralize and enforce authentication mechanisms, reducing improper authentication.

addresses: CWE-287 CWE-288

Mandates unique identification and authentication of non-organizational users, directly mitigating improper authentication.

addresses: CWE-288

Authorizing remote access reduces the ability to bypass authentication via unauthorized alternate remote channels.

addresses: CWE-287

Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.

addresses: CWE-287

Security awareness training instructs users on secure authentication practices and avoiding credential compromise.

addresses: CWE-287

Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.

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-03 partial match
blocks

Requiring authentication on every channel and path directly eliminates alternate-path bypasses.

PR.AA-05 partial match
blocks

Enforcing authorizations and least privilege across all access vectors prevents unauthenticated alternate paths.

PR.IR-01 partial match
blocks

Protecting networks and environments from unauthorized logical access blocks bypass via undocumented channels.

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.

removes
blocks

A.5.15 only requires defining a topic-specific access control policy and determining requirements; it does not itself enforce, implement or configure any access rules that would stop an alternate unauthenticated path from being exploitable.

removes
blocks

Access rights provisioning and review prevent bypass via unmonitored or alternate channels.

removes

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` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248598 There must be no ".shosts" files on the OL 8 operating system. blocks CWE-288
  • V-248827 OL 8 must not have the rsh-server package installed. blocks CWE-288
Oracle Linux 9 (2 rules)
  • V-271757 OL 9 file systems must not contain shosts.equiv files. blocks CWE-288
  • V-271758 OL 9 file systems must not contain .shosts files. blocks CWE-288
RHEL 7 (3 rules)
  • V-204440 Red Hat Enterprise Linux operating systems version 7.2 or newer using Unified Extensible Firmware Interface (UEFI) must require authentication upon booting into single-user and maintenance modes. blocks CWE-288
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. blocks CWE-288
  • V-204424 The Red Hat Enterprise Linux operating system must not allow accounts configured with blank or null passwords. blocks CWE-288

References