CVE-2018-18325

What is DotNetNuke (DNN)?

DotNetNuke (rebranded DNN Platform) is an open-source content management system and web application framework built on Microsoft's .NET stack, used for corporate intranets, portals, and public-facing websites. It relies on cryptographic protection for certain input parameters passed between client and server, an assumption the application depends on to prevent client-side tampering.

Overview

CVE-2018-18325 is the direct successor to CVE-2018-15811: after DNN's initial patch for the inadequate encryption strength issue proved incomplete, this CVE was assigned to track and resolve the remaining weakness in the same weak-encryption input-parameter protection mechanism. In effect, an attacker could still break the encryption scheme protecting input parameters even after applying the first round of fixes.

Technical Details

Like its predecessor, the flaw (CWE-326, Inadequate Encryption Strength) stems from use of a cryptographic algorithm that does not provide sufficient strength to prevent an attacker from recovering the underlying key or otherwise forging valid encrypted parameter values. Because this CVE specifically represents a patch gap, organizations that only applied the original CVE-2018-15811 fix without following up on this one remained exposed to the same class of tampering (CVSS 7.5, confidentiality impact, no privileges or user interaction required to attempt exploitation).

Discovery

This vulnerability was identified as a follow-up correction to the original DNN security release for CVE-2018-15811, indicating the DNN development team or the broader community found the first fix did not fully close the underlying weakness.

Exploitation Context

CISA's KEV entry confirms this vulnerability has been exploited in the wild. Its existence as a "patch bypass" of a previously fixed CVE is a useful reminder that organizations should always confirm they are on the fully current, latest patched release rather than assuming an earlier CVE fix fully closed a given vulnerability class.

Remediation

1. Upgrade to the DNN Platform release that resolves CVE-2018-18325, not just the earlier CVE-2018-15811 fix.
2. Verify the currently deployed DNN version against the vendor's security release notes to confirm both fixes are present.
3. Rotate any application secrets or values that may have been protected only by the weak encryption scheme, out of caution.
4. Monitor for unusual or malformed input-parameter values in application logs that could indicate tampering attempts.
5. Establish a process to track vendor security bulletins for DNN going forward, given the precedent of an incomplete initial fix.