Authenticated code execution via MeetingPollHandler deserialization
Published Apr 13, 2021 · Updated Aug 3, 2024
Insecure deserialization in Microsoft Exchange Server allows remote authenticated users to execute arbitrary code through OWA. MeetingPollHandler.ashx processes an attacker-controlled MeetingPollProposeOptionsRequestsBlob value as serialized .NET object data, permitting an ObjectDataProvider gadget to invoke Process.Start. Valid Exchange credentials and network access to OWA and EWS are required; successful exploitation runs commands in the Exchange server's security context.
Summary
What happened
Insecure deserialization in Microsoft Exchange Server allows remote authenticated users to execute arbitrary code through OWA. MeetingPollHandler.ashx processes an attacker-controlled MeetingPollProposeOptionsRequestsBlob value as serialized .NET object data, permitting an ObjectDataProvider gadget to invoke Process.Start. Valid Exchange credentials and network access to OWA and EWS are required; successful exploitation runs commands in the Exchange server's security context.
The record
- CVE
- CVE-2021-28482
- Published
- Apr 13, 2021
- Updated
- Aug 3, 2024
- Vendor
- Microsoft
- Product
- Microsoft Exchange Server 2013 Cumulative Update 23
- Classifications
- T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 13, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=15.00.0 <15.00.1497.015
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- PoC_CVE-2021-28482.pyproof of concept · unverified
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Technologies
Your stack
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Your stack
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