Code Injection in Microsoft SharePoint Server (CVE‑2023‑24955) Enables Remote Execution for Authenticated Site Owners
What It Is — Microsoft SharePoint Server contains a code‑injection flaw that lets an attacker who already has Site Owner privileges inject and run arbitrary code on the server.
Exploitability — The vulnerability is publicly disclosed (CVE‑2023‑24955) with a CVSS 3.1 base score of 7.5 (HIGH). No public exploit code has been released, but the attack requires only valid credentials with elevated site permissions, making it readily exploitable in poorly‑segmented environments.
Affected Products — Microsoft SharePoint Server (all supported on‑premises releases that include the vulnerable component).
Why It Matters for Trust & Control Assurance
- Demonstrates the risk of over‑privileged accounts; continuous verification of least‑privilege assignments is a core control‑area across most frameworks.
- Successful exploitation would leave forensic evidence (or lack thereof) that auditors scrutinize; robust logging and immutable audit trails become decisive proof of due diligence.
- Organizations that can surface real‑time evidence of privileged‑access activity can more confidently attest to their security posture during third‑party assessments.
Recommended Actions
- Apply Microsoft’s security update for CVE‑2023‑24955 immediately.
- Review and tighten Site Owner permissions; enforce least‑privilege for all SharePoint roles.
- Enable detailed SharePoint and IIS logging, forward logs to a centralized SIEM, and retain them for at least 90 days.
- Conduct a privileged‑access review and capture evidence of remediation for audit purposes.
Source: CISA KEV – CVE‑2023‑24955