Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-51293 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Phpjabbers Event Booking Calendar. Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 46% 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 SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability) — 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.
CVE-2023-51293 affects PHPJabbers Event Booking Calendar version 4.0, where a lack of rate limiting in the 'Forgot Password' and 'Email Settings' features enables attackers to generate an excessive volume of emails for a legitimate user. This uncontrolled resource consumption, classified under CWE-400, can lead to a Denial of Service (DoS) condition through the sheer number of emails produced. The vulnerability carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), highlighting its network-accessible nature and high availability impact.
Unauthenticated attackers (PR:N) can exploit this remotely (AV:N) with low attack complexity (AC:L) and no user interaction (UI:N) by repeatedly triggering the affected features. Successful exploitation overwhelms the target's email generation and delivery systems, causing resource exhaustion and disrupting service availability without impacting confidentiality or integrity.
Advisories on PacketStorm (http://packetstormsecurity.com/files/176495/PHPJabbers-Event-Booking-Calendar-4.0-Missing-Rate-Limiting.html and https://packetstorm.news/files/id/176495) disclose the missing rate limiting, while the vendor's product page (https://www.phpjabbers.com/event-booking-calendar/#sectionDemo) provides demo access but no patch details in the available references.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-56014
Vulnerability Data
A lack of rate limiting in the 'Forgot Password', 'Email Settings' feature of PHPJabbers Event Booking Calendar v4.0 allows attackers to send an excessive amount of email for a legitimate user, leading to a possible Denial of Service (DoS) via…
more
a large amount of generated e-mail messages.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SC-5 directly limits the effects of resource-exhaustion events that constitute uncontrolled consumption.
SC-6 enforces explicit allocation limits on resources, structurally preventing the weakness from occurring.
Process isolation confines resource consumption to separate domains, reducing blast radius without stopping the root flaw.
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.
Pre-agreed severity-based prioritization and resource allocation during incident triage reduce the likelihood that an attacker-induced resource exhaustion will overwhelm the organization before corrective action is taken.
Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.
Specifying log storage limits and rotation procedures reduces the risk that unbounded log growth will exhaust disk or memory resources and cause denial of service.
Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.
A.8.20 implements network-level protections (firewalls, segmentation, protocol hardening, monitoring, authentication of systems/devices) that can limit abuse of a resource-consuming weakness but do not stop the weakness from being exploitable; the flaw remains present in the product and can still be triggered from an authorized or internal context.
Monitoring network service usage and applying controls to restrict access when necessary limits an attacker’s ability to consume excessive resources through unrestricted or unauthenticated service calls.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-400, a class-level weakness. Rules are authored against its narrower children: CWE-770.