CVE-2023-41763
Skype for Business Elevation of Privilege Vulnerability
- CVSS
- 5.3Mediumscored by the publisher (CNA)
- Exploited in the wild
- Yes, in CISA KEV since 10 Oct 2023CISA deadline for US federal agencies: 31 Oct 2023
- EPSS
- 90.3%chance of exploitation in the next 30 daystop 0.2% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 10 Oct 2023analysed here 12 Nov 2026
Do first. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. (CISA's required action for this KEV entry)
Summary
Triage
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Microsoft Skype for Business Server 2015 CU13 | >= 9319.0 and < 6.0.9319.869Vendor says fixed in: not stated | |
| Microsoft Skype for Business Server 2019 CU7 | >= 2046.0 and < 7.0.246.530Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- microsoft:skype_for_business_server
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Partly. SSRF makes the server call a URL the attacker picks. A WAF can block well-known targets such as cloud metadata addresses, but not every internal host.
Also consider: egress filter · IMDSv2
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 10 Oct 2023.
- CISA due date
- 31 Oct 2023, the remediation deadline for US federal agencies
- CISA required action
- Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Public exploit code
- Detection templates only, no public exploit found: 1 Nuclei template
- CISA SSVC
- exploitation active, automatable yes, technical impact partialAssessed by CISA 16 Jul 2024 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Nuclei
- Skype for Business 2019 (SfB) - Blind Server-side Request Forgerydetection template, medium
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 10 Oct 2023Added to CISA KEV (exploited in the wild)
- 10 Oct 2023Published1 day later
- 31 Oct 2023CISA remediation due date (US federal agencies)20 days later
- 16 Jul 2024CISA SSVC assessment: exploitation active260 days (about 9 months) later
- 21 Oct 2025CVE record last updated462 days (about 1 year) later
- 12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | NoneThe attacker needs no prior access. | The attacker needs no prior access. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | LowPartial data disclosure. | Partial data disclosure. |
| Integrity | NoneNo unauthorised modification. | No unauthorised modification. |
| Availability | NoneThe service stays up. | The service stays up. |
Common questions
Is CVE-2023-41763 being exploited?
Yes. CVE-2023-41763 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2023-41763?
CVE-2023-41763 is rated Medium with a CVSS score of 5.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2023-41763?
Yes. A fix has been recorded for CVE-2023-41763. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2023-41763 affect?
CVE-2023-41763 affects microsoft:skype_for_business_server. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
2 references in the CVE record, grouped by the tags the record gives them.
Advisories (1)
- msrc.microsoft.com /update-guide/vulnerability/CVE-2023-41763
Other links (1)
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-41763
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Nuclei templates: detection templates
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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