High

Microsoft Exchange Server Elevation of Privilege Vulnerability

IdentifiersCVE-2019-0724CWE-346

CVE-2019-0724 is an elevation of privilege vulnerability in Microsoft Exchange Server associated with the Exchange Web Services PushSubscriptionRequest mechanism. The flaw allows Exchange to perform NTLM authentication to attacker-controlled endpoints without adequate protection, enabling an NTLM relay condition. In affected deployments, a remote attacker can induce the Exchange server to authenticate outward and relay that authentication to other services, resulting in privilege escalation. The issue affects Microsoft Exchange Server deployments in supported versions identified by Microsoft and is distinct from CVE-2019-0686, though both were addressed in the same advisory context.

For your environment

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can allow a remote attacker to obtain the privileges of the Exchange server account. In typical Active Directory environments, those privileges may be sufficient to compromise the Exchange server and potentially escalate further to domain-level administrative control, resulting in severe confidentiality, integrity, and availability impact across the enterprise.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, disable Exchange Web Services push and pull subscriptions where operationally feasible to reduce exposure. Review and remove unnecessary Exchange privileges in Active Directory, including use of Microsoft's provided PowerShell-based hardening guidance where applicable. Prioritize restricting outbound authentication paths from Exchange and limiting excessive inherited privileges until patched.

Remediation

Patch, then assume compromise.

Apply the Microsoft Exchange security updates that address CVE-2019-0724. Reported fixed versions include Exchange Server 2010 SP3 Update Rollup 26, Exchange Server 2013 CU22, Exchange Server 2016 CU12, and Exchange Server 2019 CU1 or later. The updates prevent NTLM authentication to arbitrary hosts via PushSubscriptionRequest and also reduce Exchange's default Active Directory privileges.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

Microsoft CorporationExchange Serverapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

2 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

2 SOURCESView more in app

msrc microsoftNews

Mar 2, 2021

CVE-2021-27065 - Security Update Guide - Microsoft - Microsoft Exchange Server Remote Code Execution Vulnerability

Specific vulnerability listed in the content with severity Important.

msrc microsoftNews

Mar 2, 2021

CVE-2021-26857 - Security Update Guide - Microsoft - Microsoft Exchange Server Remote Code Execution Vulnerability

Specific named vulnerability listed in the content; no product or technical description is provided beyond severity/date and tabular flags.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity