Unauthenticated network-resource discovery via SSRF
Published Oct 10, 2023 · Updated Oct 21, 2025
SSRF in Microsoft Skype for Business Server 2015 CU13 and 2019 CU7 allows remote attackers to query arbitrary network addresses. A crafted network call makes the server parse an HTTP request to an attacker-chosen address, exposing reachable IP addresses and port numbers. No authentication or user interaction is required, and the consequence is limited to network-resource discovery rather than data modification or service interruption.
Summary
What happened
SSRF in Microsoft Skype for Business Server 2015 CU13 and 2019 CU7 allows remote attackers to query arbitrary network addresses. A crafted network call makes the server parse an HTTP request to an attacker-chosen address, exposing reachable IP addresses and port numbers. No authentication or user interaction is required, and the consequence is limited to network-resource discovery rather than data modification or service interruption.
The record
- CVE
- CVE-2023-41763
- Published
- Oct 10, 2023
- Updated
- Oct 21, 2025
- Vendor
- Microsoft
- Product
- Skype for Business Server
- Classifications
- CWE-918, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 10, 2023Exploitation reportedCISA Known Exploited Vulnerabilities catalog listing
- Oct 10, 2023CVE publishedPublication date reported by the CVE source.
- Oct 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2046.0 <7.0.246.530
- Affected versionversion=9319.0 <6.0.9319.869
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Reported exploitation
- CISA Known Exploited Vulnerabilities catalog listingknown exploited catalog
Technologies
Your stack
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Your stack
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