Emerging Threatcriticaltest
CVE-2021-33766 Exchange ProxyToken Exploitation
Detects the exploitation of Microsoft Exchange ProxyToken vulnerability as described in CVE-2021-33766
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Launch
Florian Roth (Nextron Systems), Max Altgelt (Nextron Systems), Christian Burkard (Nextron Systems)Created Mon Aug 30Updated Mon Jan 0256973b50-3382-4b56-bdf5-f51a3183797a2021
Emerging Threat
Active Threat
Developed to detect an active or emerging threat. Prioritize investigation of any alerts and correlate with threat intelligence.
Log Source
Web Server Log
CategoryWeb Server Log← raw: webserver
HTTP access logs from web servers capturing request paths, methods, and status codes.
Detection Logic
Detection Logic2 selectors
detection:
selection_1:
cs-method: 'POST'
cs-uri-query|contains|all:
- '/ecp/'
- '/RulesEditor/InboxRules.svc/NewObject'
sc-status: 500
selection_2:
cs-uri-query|contains|all:
- 'SecurityToken='
- '/ecp/'
sc-status: 500
condition: 1 of selection_*False Positives
Unknown
False positive likelihood has not been assessed. Additional context may be needed during triage.
References
MITRE ATT&CK
Tactics
Other
cve.2021-33766detection.emerging-threats
Rule Metadata
Rule ID
56973b50-3382-4b56-bdf5-f51a3183797a
Status
test
Level
critical
Type
Emerging Threat
Created
Mon Aug 30
Modified
Mon Jan 02
Author
Path
rules-emerging-threats/2021/Exploits/CVE-2021-33766/web_cve_2021_33766_msexchange_proxytoken.yml
Raw Tags
attack.initial-accessattack.t1190cve.2021-33766detection.emerging-threats