Security readout for executives and security teams
Plain-English summary
This is a high-severity Microsoft SharePoint Server issue that could let an unauthenticated attacker deceive a user and cause serious confidentiality, integrity, and availability impact. The public bundle identifies affected on-premises SharePoint Server 2016, 2019, and Subscription Edition versions. No provided source confirms active exploitation.
Executive priority
Treat this as a high-priority SharePoint patching item, especially for externally reachable portals or collaboration sites handling sensitive data. There is no provided evidence of active exploitation, but the potential business impact is high enough to justify timely remediation tracking.
Technical view
CVE-2023-33159 is listed as a SharePoint Server spoofing vulnerability with CWE-79 and CVSS 3.1 score 8.8. The vector is network-accessible, low complexity, no privileges required, and user interaction required. The supplied CVSS data shows high confidentiality, integrity, and availability impact, with official remediation available.
Likely exposure
Exposure is likely for organizations running Microsoft SharePoint Enterprise Server 2016, SharePoint Server 2019, or SharePoint Server Subscription Edition matching the affected version data. Internet-facing or broadly accessible SharePoint deployments increase business relevance, especially where users can be induced to interact with attacker-controlled content or links.
Exploitation context
The source bundle does not show CISA KEV listing or any cited evidence of active exploitation. CVSS exploit maturity is marked unproven. The risk is still meaningful because exploitation is network-based, low complexity, unauthenticated, and can have high impact if a user interacts.
Researcher notes
Public details are limited. The bundle identifies spoofing, CWE-79, affected SharePoint products, CVSS impact, and MSRC remediation status, but not root cause detail or exploit mechanics. Avoid assuming exploitation patterns beyond user interaction and the CVSS vector.
Mitigation direction
- Apply the Microsoft remediation referenced in the MSRC advisory.
- Confirm fixed SharePoint build numbers against Microsoft guidance.
- Prioritize externally reachable and business-critical SharePoint farms.
- Restrict unnecessary SharePoint exposure until patching is complete.
- Review Microsoft guidance for any deployment-specific prerequisites.
Validation and detection
- Inventory SharePoint Server editions and versions in use.
- Compare installed builds with the MSRC affected and fixed version data.
- Confirm patch installation across every SharePoint farm member.
- Check whether any affected SharePoint services are internet-accessible.
- Review SharePoint and identity logs for suspicious user-session activity.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2023-33159 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- Microsoft SharePoint Server Spoofing VulnerabilityCVE reference · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.