Detection rules › YARA-L
SharePoint CVE-2025-49706 Exploitation
This rule detects attempts to exploit CVE-2025-49706 in SharePoint by observing POST requests to a vulnerable aspx path, which could result in code execution or server compromise.
Known false positives
- Legitimate administrative actions to the specified URL should be rare. Some penetration testing activity could trigger this rule. In some cases, specific third party applications could generate similar requests, but this should be rare.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Lateral Movement |
References
Rule body
// Copyright 2025 Google LLC. Licensed under Apache-2.0.
rule ttp_sharepoint_cve_2025_49706_exploitation {
meta:
author = "Google Cloud Security"
rule_name = "SharePoint CVE-2025-49706 Exploitation"
description = "This rule detects attempts to exploit CVE-2025-49706 in SharePoint by observing POST requests to a vulnerable aspx path, which could result in code execution or server compromise."
severity = "High"
tactic = "TA0002"
technique = "T1210"
false_positives = "Legitimate administrative actions to the specified URL should be rare. Some penetration testing activity could trigger this rule. In some cases, specific third party applications could generate similar requests, but this should be rare."
reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-49706, https://research.eye.security/sharepoint-under-siege/"
rule_id = "mr_661defd1-34e0-47ef-8073-a761244714e3"
events:
$e.network.http.method = "POST"
$e.target.url = /_layouts\/1(5|6)\/ToolPane\.aspx/ nocase
$e.target.url = /DisplayMode=Edit/ nocase
$e.target.url = /a=\/ToolPane\.aspx/ nocase
$e.network.http.referral_url = /^\S*\/_layouts\/1(5|6)\/signout\.aspx(\?.*)?$/ nocase
$e.network.application_protocol = "HTTP" // Prefilter for HTTP protocol
$prnc_ip = $e.principal.ip
$trgt_ip = $e.target.ip
match:
$prnc_ip, $trgt_ip over 5m
outcome:
$risk_score = max(90)
$vendor_name = array_distinct($e.metadata.vendor_name)
$product_name = array_distinct($e.metadata.product_name)
$result = "attempted"
$result_time = max($e.metadata.event_timestamp.seconds)
$target_url = array_distinct($e.target.url)
$user_agent = array_distinct($e.network.http.user_agent)
$referrer = array_distinct($e.network.http.referral_url)
$principal_ip = array($prnc_ip)
$target_ip = array($trgt_ip)
$event_count = count($e.metadata.id)
$target_application = array_distinct($e.target.application)
condition:
$e
}
YARA-L rule structure
Condition
Fires when at least one $e event in the 5m window.
Events
$e
network.http.method = "POST"target.url matches "_layouts\/1(5|6)\/ToolPane\.aspx"target.url matches "DisplayMode=Edit"target.url matches "a=\/ToolPane\.aspx"network.http.referral_url matches "^\S*\/_layouts\/1(5|6)\/signout\.aspx(\?.*)?$"network.application_protocol = "HTTP"
Match and correlation
Outcome
Outcome variables add context to a detection. When the rule generates an alert, $risk_score is displayed with it.
| Field | Expression |
|---|---|
risk_score | max(90) |
vendor_name | array_distinct($e.metadata.vendor_name) |
product_name | array_distinct($e.metadata.product_name) |
result_time | max($e.metadata.event_timestamp.seconds) |
target_url | array_distinct($e.target.url) |
user_agent | array_distinct($e.network.http.user_agent) |
referrer | array_distinct($e.network.http.referral_url) |
principal_ip | array($prnc_ip) |
target_ip | array($trgt_ip) |
event_count | count($e.metadata.id) |
target_application | array_distinct($e.target.application) |