Cyber Resilience

CVE-2023-40756

Phpjabbers Callback Widget 1.0

Published
28 August 2023
Modified
21 November 2024
Patch / advisory
View 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 0.0075 52th percentile
Risk Priority 72 floored blend · peak EPSS

Summary

CVE-2023-40756 is a critical-severity Observable Discrepancy (CWE-203) vulnerability in Phpjabbers Callback Widget. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Account Discovery (T1087); ranked in the top 48% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

User enumeration is found in PHPJabbers Callback Widget v1.0. This issue occurs during password recovery, where a difference in messages could allow an attacker to determine if the user is valid or not, enabling a brute force attack with valid…

more

users.

CWE(s)
CWE-203

Related Threats

MITRE ATT&CK Enterprise Techniques

T1087 Account Discovery Discovery
Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment.
attack.mitre.org →
T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
T1595 Active Scanning Reconnaissance
Adversaries may execute active reconnaissance scans to gather information that can be used during targeting.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-36314Same product: Phpjabbers Callback Widget
CVE-2023-40755Same product: Phpjabbers Callback Widget
CVE-2023-36312Same product: Phpjabbers Callback Widget
CVE-2023-36127Same vendor: Phpjabbers
CVE-2023-36315Same product: Phpjabbers Callback Widget
CVE-2024-45089Shared CWE-203
CVE-2024-0564Shared CWE-203
CVE-2025-27667Shared CWE-203
CVE-2025-21510Shared CWE-203
CVE-2023-3462Shared CWE-203

Affected Assets

phpjabbers
callback widget
1.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

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Detect
Catch it (NIST detect / respond)

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Harden
Shrink the surface (DISA STIG)
  • 1 hardening rule · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

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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.

SC-30 Concealment and Misdirection
addresses: CWE-203

Misdirection can normalize or falsify responses to eliminate observable discrepancies that aid reconnaissance.

SC-31 Covert Channel Analysis
addresses: CWE-203

Observable discrepancies in system behavior can be modulated to create covert storage or timing channels; the required analysis detects and constrains such avenues.

SI-11 Error Handling
addresses: CWE-203

Prevents attackers from using observable differences in error responses to infer internal system details or state.

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 observable response discrepancies via consistent error handling and timing.

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.8.17 Clock synchronization none match
none

Accurate, synchronized timestamps reduce observable timing discrepancies that an attacker could exploit to infer sensitive information or distinguish between success and failure paths.

References