Critical

Microsoft Exchange Memory Corruption Remote Code Execution Vulnerability

IdentifiersCVE-2018-8302CWE-119

CVE-2018-8302 is a critical remote code execution vulnerability in Microsoft Exchange Server caused by improper handling of objects in memory. The flaw is described by Microsoft as a memory corruption issue in Exchange. Successful exploitation could allow attacker-controlled data to corrupt process memory and redirect execution flow, resulting in arbitrary code execution in the context of the vulnerable Exchange service. The available information identifies the issue as affecting Microsoft Exchange Server, but does not provide public detail on the exact vulnerable function, protocol surface, or triggering code path.

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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 result in remote code execution on a vulnerable Microsoft Exchange Server. This can enable full compromise of the targeted Exchange application context, including execution of arbitrary code, theft or manipulation of mail-related data, installation of additional payloads, and potential follow-on activity such as persistence or lateral movement depending on the privileges of the Exchange service account and surrounding environment.

Mitigation

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

If immediate patching is not possible, reduce exposure of Exchange services to untrusted networks, restrict access to Exchange-facing interfaces to only required clients and administrative paths, and monitor Exchange processes for signs of abnormal child-process creation, crashes, or exploitation attempts. Network segmentation, least-privilege service configuration, and rapid detection of suspicious activity on Exchange hosts can reduce risk, but no reliable mitigation is available that fully eliminates the vulnerability short of applying the vendor fix.

Remediation

Patch, then assume compromise.

Apply the Microsoft security updates released for CVE-2018-8302 on supported Microsoft Exchange Server versions. Because the available information does not specify exact affected builds in this dataset, remediation should consist of identifying deployed Exchange versions and installing the corresponding vendor-issued August 2018 security update or a later cumulative update that includes the fix. Standard post-patching validation should confirm that all Exchange roles and nodes have been updated consistently.

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

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

3 SOURCESView more in app

medium peterjsonNews

Nov 19, 2021

Some notes about Microsoft Exchange Deserialization RCE (CVE-2021-42321) | by Peterjson | Medium

A referenced Exchange deserialization vulnerability mentioned only as historical comparison.

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 Critical.

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