CVE-2023-41763
SSRF in Microsoft Skype For Business Server 2015 … 2019
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NSummary
CVE-2023-41763 is a medium-severity SSRF (CWE-918) vulnerability in Microsoft Skype For Business Server. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
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-2023-41763 is an elevation-of-privilege vulnerability in Skype for Business that stems from a server-side request forgery flaw (CWE-918). The affected component allows an unauthenticated network attacker to cause the server to issue requests to arbitrary destinations, resulting in limited information disclosure as reflected in its CVSS 5.3 score (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N).
An attacker with no credentials or user interaction can send crafted requests over the network to a Skype for Business server and obtain partial confidential data that would otherwise be inaccessible. Because the vulnerability requires no authentication and has a low attack complexity, it can be exploited from anywhere on the network reachable by the service.
Microsoft’s security update guide and the CISA Known Exploited Vulnerabilities catalog both reference the issue, indicating that administrators should apply the patches supplied through the standard Microsoft Update channels to eliminate the SSRF vector.
The EPSS score for this CVE rose sharply from a low baseline after disclosure, reaching a peak of 0.7335 on 2024-11-11 before receding to its current value of 0.1650; its inclusion in the CISA KEV catalog further confirms observed in-the-wild exploitation activity.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-46255
Vulnerability Data
Skype for Business Elevation of Privilege Vulnerability
- CWE(s)
- KEV Date Added
- 10 October 2023
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
—
V1.3.6V1.5.3V5.3.2V10.4.7
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.
Penetration testing attempts server-side requests to internal resources, identifying SSRF weaknesses for remediation.
Outbound connections to external resources can be monitored and limited at the boundary, reducing SSRF impact.
Validates server-side URLs and resource references to block SSRF attempts.
Detects server-side request forgery through monitoring of unexpected outbound connections.
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.
Secure development practices directly include input validation and destination allow-listing that prevent SSRF.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
Network segmentation and egress controls can limit the damage from successful SSRF requests.
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.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.