{"cveID":"CVE-2021-34523","vendorProject":"Microsoft","product":"Exchange Server","vulnerabilityName":"Microsoft Exchange Server Privilege Escalation Vulnerability","dateAdded":"2021-11-03","shortDescription":"Microsoft Exchange Server contains an unspecified vulnerability that allows for privilege escalation.","requiredAction":"Apply updates per vendor instructions.","dueDate":"2021-11-17","knownRansomwareCampaignUse":"Known","notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-34523","cwes":["CWE-287"],"year":2021,"state":"mapped","stale_reasons":[],"mappings":[{"domain":"enterprise","cve":"CVE-2021-34523","technique":"T1190","technique_name_at_mapping":"Exploit Public-Facing Application","mapping_type":"exploitation_technique","capability_group":"priv_escalation","comments":"This privilege escalation vulnerability can be exploited by sending a specially crafted HTTP request to the exchange server, is it often chained together with CVE-2021-34473, a remote code execution vulnerability.","references":["https://cloud.google.com/blog/topics/threat-intelligence/pst-want-shell-proxyshell-exploiting-microsoft-exchange-servers"],"status":"complete","source_file":"kev-07.28.2025_attack-16.1-enterprise.json","attack_version":"16.1","kev_snapshot":"07/28/2025"}],"techniques":[{"id":"T1190","domains":["enterprise"],"in_current_bundle":true,"live":true,"name_now":"Exploit Public-Facing Application","name_at_mapping":"Exploit Public-Facing Application","renamed":false,"revoked_by":null,"mapping_types":["exploitation_technique"],"sigma_rule_count":149,"has_detection_strategy":true}],"mapping_types":["exploitation_technique"],"has_exploitation_technique":true,"mapping_attack_versions":["16.1"],"mapping_domains":["enterprise"],"sigma_coverage":"full","sigma_rules_tagged_cve":[],"added_after_mapping_snapshot":false,"_source":"kevmap","_built":"2026-08-23 05:47 UTC","_attack_version":"19.2"}