Name:Linux Suspicious React or Next.js Child Process id:cda04e9c-1950-43ab-87d6-e333a3d7f107 version:4 date:None author:Nasreddine Bencherchali, Splunk status:production type:TTP Description:This analytic detects Linux processes such as sh, bash, and common Linux LOLBINs being spawned by React or Next.js application servers.
In the context of CVE-2025-55182 / React2Shell / CVE-2025-66478 for Next.js, successful exploitation can lead to arbitrary JavaScript execution on the server, which in turn is commonly used to invoke Node's child_process APIs (for example child_process.execSync) to run OS-level commands.
Public proof-of-concept payloads and observed in-the-wild exploit traffic show patterns where the vulnerable React Server Components handler triggers process.mainModule.require('child_process').execSync() to execute binaries such as ping, curl, or arbitrary shells on the underlying host.
This detection focuses on suspicious child processes where a Next/React server process spawns an uncommon process.
Such activity might be a strong indicator of exploitation of the aforementioned vulnerability.
Data_source:
-Sysmon for Linux EventID 1
search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name = "node" Processes.parent_process IN ( "*--experimental-https*", "*--experimental-next-config-strip-types*", "*/node_modules/next*", "*next dev*", "*next start*", "*node_modules/.bin*", "*react-scripts start*", "*start-server.js*" ) AND ( Processes.process_name IN ( "awk", "gawk", "ifconfig", "lua", "nc", "ncat", "netcat", "openssl", "perl", "php", "python", "python2", "python3", "ruby", "socat", "telnet" ) OR ( Processes.process_name IN ("curl", "wget") Processes.process = "*|*" ) OR ( Processes.process_name IN ( "bash", "dash", "sh" ) NOT Processes.process = "*-c*" ) OR ( Processes.process_name IN ( "bash", "dash", "ksh", "sh", "zsh" ) Processes.process IN ( "*/dev/tcp/*", "*/dev/udp/*", "*0>&1*", "*curl*", "*exec *>&*", "*fsockopen*", "*ifconfig*", "*mkfifo*", "*nc *", "*ncat*", "*netcat*", "*proc_open*", "*s_client*", "*socat*", "*socket*", "*subprocess*", "*TCPSocket*", "*wget*" ) ) )
how_to_implement:The detection is based on data that originates from Endpoint Detection and Response (EDR) agents.
These agents are designed to provide security-related telemetry from the endpoints where the agent is installed.
To implement this search, you must ingest logs that contain the process GUID, process name, and parent process.
Additionally, you must ingest complete command-line executions.
These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model.
Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives:Rare false positives might show up from child processes such as sh. Apply additional filters as needed.
References: -https://react.dev/blog/2025/12/03/critical-security-vulnerability-in-react-server-components -https://nextjs.org/blog/CVE-2025-66478 -https://nvd.nist.gov/vuln/detail/CVE-2025-55182 -https://gist.github.com/maple3142/48bc9393f45e068cf8c90ab865c0f5f3 -https://www.wiz.io/blog/critical-vulnerability-in-react-cve-2025-55182 drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'7d' latest_offset:'0' analytic_story:['React2Shell']
