CVE-2021-48016 DedeCMS CVE debrief

Who should care

System administrators and security teams responsible for DedeCMS installations should assess their exposure and take steps to remediate the vulnerability. This includes reviewing and updating DedeCMS versions, implementing input validation and sanitization, and monitoring for suspicious activity. Additionally, operators and platform administrators should be aware of the potential for unauthenticated remote code execution and take steps to protect their  /

Why it matters

CVE-2021-48016 is a critical vulnerability in DedeCMS 5.8.1-beta that allows unauthenticated remote code execution, posing a significant risk to affected systems.

• Potential for unauthenticated remote code execution
• Possible exploitation by attackers to execute arbitrary PHP and system commands
• Need for input validation and sanitization to prevent similar vulnerabilities

Technical summary

The vulnerability is caused by a PHP code injection issue in the ShowMsg() function, where the HTTP Referer header is written into a DedeTemplate string and included. An attacker can exploit this vulnerability by sending a crafted Referer header to the /plus/flink.php?dopost=save endpoint with an empty validate code, allowing them to execute arbitrary PHP and system commands. This vulnerability affects DedeCMS 5.8.1-beta and could allow unauthenticated remote code execution, posing a significant risk to affected systems.

Defensive priority

High

Recommended defensive actions

• Review and update DedeCMS versions to ensure they are not vulnerable
• Implement input validation and sanitization for user-supplied data
• Monitor for suspicious activity and implement logging and auditing
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The vulnerability was first observed by the Shadowserver Foundation on 2023-10-14. The CVE record and source item provide details about the vulnerability, including its CVSS score and affected versions.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.