Microsoft SharePoint, a cornerstone of collaboration in most enterprises — and a prime target for adversaries — has disclosed a zero day.
Recently catalogued as CVE-2023-29357, this zero-day vulnerability in SharePoint Server allows attackers to bypass authentication entirely using a forged JSON Web Token (JWT). The attacker doesn’t need a valid password. They don’t need to exploit misconfigured permissions. They just need to trick SharePoint into believing they’re a trusted identity — and from there, it’s game over.
For most security teams, this kind of attack flies completely under the radar.
What makes the SharePoint zero-day so dangerous?
Let’s break it down:
- No password theft required
This isn’t credential stuffing or phishing. The attacker never touches the login screen. - Bypasses MFA and SSO
Since the token is forged, identity providers (IdPs) like Okta, Azure AD, and Duo aren’t even in the loop. - Appears legitimate in logs
To your SIEM, your EDR, and even your identity provider, it looks like a standard, valid session. The attacker’s actions are buried among millions of others from real users.
This is identity subversion at its worst: not stolen passwords, but stolen trust.
Why traditional security tools miss this
Most organizations rely on a mix of endpoint agents, network detection, and identity provider logs to catch suspicious activity. But in this case:
- EDR sees nothing unless the attacker drops malware (which they often don’t).
- SIEMs see isolated log events — but without deep identity context, it’s just noise.
- IAM systems aren’t breached, so they don’t raise an alarm.
The result? Weeks or months of undetected access, lateral movement, and privilege escalation — all under a trusted identity.
How Mesh Security helps: Identity in full context
Mesh Security is purpose-built to solve this exact problem. We’re the first platform that unifies identity data, security telemetry, and real-time context across all your tools and infrastructure, enabling deep identity observability and cross-domain detection.
Here’s how Mesh helps close the gaps exposed by the SharePoint vulnerability:
1. Detect anomalous identity behavior — even when the login looks clean
Mesh continuously maps behavior across every identity — human and machine — comparing it to normal activity across SaaS, cloud, endpoints, and infrastructure. So when a “valid” token is used in unexpected ways — from a suspicious location, triggering admin actions, or accessing sensitive data out of pattern — Mesh raises the flag.
2. Correlate signals across your entire stack — not just IAM
Because Mesh ingests and correlates signals from Okta, Azure AD, CrowdStrike, M365, GCP, AWS, across multi-SIEM, and beyond, we don’t rely on a single source of truth. We build a contextual identity graph — allowing Mesh to detect risky access even when no individual system thinks it’s unusual.
3. Expose dormant privilege paths and shadow access
Mesh maps identity chaining across your environment — showing which service accounts, OAuth tokens, or API keys can be abused to elevate access. This means even if an attacker gets in through SharePoint, Mesh can show you how they might pivot — and how to stop it.
The future of detection is identity-first
The SharePoint zero-day isn’t just a Microsoft problem — it’s a visibility problem. It proves that identity can no longer be treated as a control plane alone. It must be part of the detection and response plane too.
Mesh Security makes that possible.
If you’re relying solely on your IdP or EDR to detect identity threats, you’re already behind. With Mesh, you get enterprise-wide identity observability — context-rich, real-time, and designed to catch the things others miss.
Don’t wait for the next zero-day. Unify your tools. See the full picture. Detect faster. Respond smarter. With Mesh.
