CVE-2025-3816 Overview
CVE-2025-3816 is an operating system command injection vulnerability in westboy CicadasCMS 2.0. The flaw resides in the Scheduled Task Handler component, specifically in the /system/schedule/save endpoint. An authenticated remote attacker can manipulate unspecified parameters to inject arbitrary operating system commands. The vulnerability is tracked under [CWE-77] and [CWE-78], covering improper neutralization of special elements used in commands. Public disclosure occurred through a GitHub issue, and the exploit details are available to the public.
Critical Impact
Authenticated attackers can execute arbitrary OS commands on the underlying server, potentially compromising the CicadasCMS host and any data it processes.
Affected Products
- westboy CicadasCMS 2.0
- westboy CicadasCMS 1.0 (per CPE listing)
- Deployments exposing the Scheduled Task Handler endpoint to authenticated users
Discovery Timeline
- 2025-04-19 - CVE-2025-3816 published to the National Vulnerability Database
- 2025-10-01 - Last updated in NVD database
Technical Details for CVE-2025-3816
Vulnerability Analysis
The vulnerability stems from improper neutralization of special elements in the Scheduled Task Handler of CicadasCMS 2.0. The /system/schedule/save endpoint accepts attacker-controlled input that is concatenated into a shell command without adequate sanitization. Because scheduled task definitions in many content management systems map directly to shell or interpreter invocations, this design pattern frequently produces command injection when input validation is absent.
Exploitation requires network access to the management interface and high privileges, since the schedule editor sits behind authenticated administrative areas. The exploit prediction score for this issue is 0.496%, placing it in the 66th percentile of scored vulnerabilities. The exploit has been publicly disclosed, increasing the probability that opportunistic actors will weaponize it against exposed instances.
Root Cause
The root cause is missing input sanitization in the scheduled task save routine. User-supplied fields are passed into an operating system command without escaping shell metacharacters such as ;, |, &, backticks, or $(). This pattern matches the description for [CWE-78]: improper neutralization of special elements used in an OS command.
Attack Vector
The attack vector is network-based. An attacker authenticates to the CicadasCMS administrative interface, navigates to the schedule creation feature, and submits a crafted payload to /system/schedule/save. The injected metacharacters break out of the intended command context and execute attacker-chosen commands with the privileges of the CicadasCMS process.
No verified proof-of-concept code is mirrored in this advisory. Refer to the GitHub issue discussion and the VulDB entry for technical reproduction details.
Detection Methods for CVE-2025-3816
Indicators of Compromise
- Unexpected child processes spawned by the CicadasCMS application user, such as sh, bash, cmd.exe, powershell.exe, curl, or wget.
- HTTP POST requests to /system/schedule/save containing shell metacharacters (;, |, &&, `, $() in task name or command fields.
- New or modified scheduled task entries in the CicadasCMS database that contain inline shell syntax.
- Outbound network connections originating from the web application process to unfamiliar hosts shortly after schedule edits.
Detection Strategies
- Inspect web server access logs for authenticated requests to /system/schedule/save followed by anomalous process creation events.
- Correlate administrative session activity with process lineage to flag web-app-spawned shells.
- Apply web application firewall rules that block shell metacharacters in schedule-related POST parameters.
- Use endpoint behavioral analytics to identify abnormal command chains rooted in the Java or PHP runtime hosting CicadasCMS.
Monitoring Recommendations
- Forward CicadasCMS access logs and host process telemetry to a central SIEM for correlation.
- Alert on any execution of interpreters (sh, bash, powershell) under the CMS service account.
- Monitor for outbound connections from the web tier to external IP addresses not on an established allowlist.
How to Mitigate CVE-2025-3816
Immediate Actions Required
- Restrict access to the CicadasCMS administrative interface using network segmentation, VPN, or IP allowlists.
- Audit current administrator accounts and rotate credentials for any account capable of editing scheduled tasks.
- Review existing scheduled task entries for unauthorized modifications or embedded shell payloads.
- Run the CicadasCMS process under a least-privileged service account that cannot execute system administration tools.
Patch Information
No vendor patch is referenced in the NVD entry or linked advisories at the time of publication. Track the VulDB entry and the upstream project issue tracker for fix availability. Until a patch is released, treat the deployment as exposed and apply compensating controls.
Workarounds
- Disable the Scheduled Task Handler feature if it is not required for business operations.
- Place the application behind a web application firewall that strips or rejects shell metacharacters in /system/schedule/save parameters.
- Restrict the operating system user running CicadasCMS so it cannot invoke shells, package managers, or network utilities.
- Enable verbose audit logging on the application server to capture any successful exploitation attempts for forensic review.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
