Description

The wpmudev-updates WordPress plugin before 5.0.1 does not verify the integrity of the packages installed through its remote management interface, nor protect those requests against replay, allowing an attacker able to obtain or replay a valid signed management request to install and execute arbitrary code (remote code execution).

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-08-12T06:18:15.680Z",
  "pubdate": "2026-08-12T06:18:15.680Z",
  "executiveSummary": "The wpmudev-updates WordPress plugin before 5.0.1 suffers from a critical remote code execution vulnerability stemming from inadequate cryptographic integrity verification and a lack of anti-replay protections within its remote management interface.\nAn unauthenticated or remote attacker who is capable of obtaining or intercepting a valid signed management request can replay the transaction to force the target system to install and execute arbitrary code.\nThis vulnerability directly impacts the administrative remote management capabilities of the plugin, exposing affected WordPress installations to complete system compromise.\nThe inherent risks include unauthorized administrative access, persistent backdoor installation, full data exfiltration, and total control over the underlying web application environment.\nSuccessful exploitation requires the attacker to capture or otherwise obtain a legitimate, cryptographically signed management request previously issued by an authorized entity.\nOnce the valid request is replayed against the vulnerable endpoint, the application processes the installation routine without performing requisite validation checks on package integrity or request freshness.",
  "technicalDetails": "The root cause of this vulnerability lies in the remote management interface of the wpmudev-updates plugin, which fails to enforce robust cryptographic integrity checks on incoming software packages and lacks request replay prevention mechanisms such as nonces, timestamps, or sequential counters.\nThe vulnerable component is responsible for handling remote installation routines and package deployments via the management interface in versions of the wpmudev-updates WordPress plugin prior to 5.0.1.\nAlthough the initial management requests may rely on a cryptographic signature, the absence of replay protection allows an adversary to capture network traffic and indefinitely reuse valid signed payloads.\nThe attack flow proceeds as follows: First, an attacker monitors network traffic or compromises an intermediary communication channel to intercept a legitimate, signed remote management request containing instructions to download and install a package.\nSecond, the attacker stores this valid signed request and subsequently replays it toward the vulnerable remote management interface of the target WordPress site.\nThird, the application receives the replayed request and improperly trusts the signature without validating whether the request has already been processed or if the associated software package has been altered.\nFourth, the system proceeds to download and install the payload via the plugin's remote management functionality.\nFinally, the installation of the arbitrary package leads directly to remote code execution within the context of the web server user, allowing the attacker to execute arbitrary commands, deploy malicious backdoors, or pivot further into the hosting environment.\nThe vulnerability is exposed over the network via HTTP/HTTPS endpoints handled by the WordPress plugin.\nExploitation does not inherently require prior authentication to the WordPress instance if the management interface is publicly accessible and accepts the replayed signed request directly, relying entirely on the reuse of valid cryptographic signatures."
}