CriticalCVE-2018-18325

    DotNetNuke (DNN) Inadequate Encryption Strength Vulnerability (CVE-2018-18325)

    Published In CISA KEV since Sources: CVE.org, OSV

    What is affected, what to do

    DNN (aka DotNetNuke) 9.2 through 9.2.2 uses a weak encryption algorithm to protect input parameters. NOTE: this issue exists because of an incomplete fix for CVE-2018-15811.

    The vulnerability is being actively exploited; treat it as a priority. The available sources name no fixed version. Check the vendor guidance in the references below. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Dnn.Platform lte 9.2..9.2.2

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    7.5

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    7.5

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: CVE.org, OSV

    74.1 %

    EPSS score

    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.

    Source: FIRST EPSS, percentile 99.48

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    216.67 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

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    actively exploited
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    7.5 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.5
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

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    74.1 %
    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    99.48
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    CISA assessment (SSVC)
    Exploitation: active · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 4 February 2025
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-326

    Response and mitigation

    Why act now?

    Prioritisation rationale

    The weak parameter encryption is the missing link that lets the well-known DNNPersonalization cookie deserialization attack work against DNN 9.2.x. A nominally confidentiality-only flaw therefore becomes, in practice, unauthenticated remote code execution over the network. Mature public exploit modules and a very high exploitation likelihood make this a staple of automated mass scanning. Neglected corporate, municipal and association portals are the typical victims. Ransomware use is not flagged. Treat any internet-reachable DNN instance in the affected range as critical and upgrade or isolate it now. Internal-only instances are high priority but come second.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory: Find every internet-facing DNN instance. Check the version under Settings > About or via the file version of bin\DotNetNuke.dll. Affected are 9.2 through 9.2.2 and legacy builds based on dotnetnuke.core 7.x (NuGet). Both branches are out of vendor support.
      • Patch: Upgrade to a current, supported DNN release. The patch is available from the vendor — look up the fixed version in the vendor advisory (DNN Security Center). A build that only fixes CVE-2018-15811 is not enough; this CVE exists precisely because that fix was incomplete.
      • Isolate if you cannot upgrade today: Put the site behind a reverse proxy or WAF with an IP allowlist, or take it offline temporarily. Prioritise instances with public user registration enabled.
      • Rotate key material: After upgrading, regenerate machineKey (validationKey/decryptionKey) in web.config and keep all web-farm nodes in sync. Then rotate host and admin passwords.
      • Compromise assessment: Diff the webroot (\Portals\, \DesktopModules\, site root) for new or modified .aspx, .ashx and .asmx files across the exposure window. Also review the Users table for unknown superusers (IsSuperUser=1).

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: Host DNN in a DMZ and restrict outbound traffic from the IIS app pool (default-deny egress). This makes reverse shells and tool downloads harder.
      • WAF/IPS: Block requests to non-existent paths that carry a DNNPersonalization cookie. The public exploit path, including the Metasploit module dnn_cookie_deserialization_rce, abuses the 404 handler. Also drop oversized or base64-like values in that cookie.
      • Configuration: Disable public registration (Site Settings > Security > User Registration = None). Registration gives attackers the plaintext/ciphertext pairs they need to attack the weak scheme.
      • Endpoint hardening: Run the app pool under a dedicated low-privilege identity. Use AppLocker or WDAC to stop w3wp.exe from launching cmd.exe, powershell.exe, certutil.exe or rundll32.exe.
      • Least privilege: Limit app-pool write access to \Portals\. Remove script execution from upload folders via IIS handler mappings.
      • Lifecycle management: Treat 7.x and 9.2.x as end-of-life and track their migration in the risk register.

    3. Runbook step 3

      Detection rules

      • IIS access log: Bursts of 404s on random paths that arrive with a DNNPersonalization cookie indicate exploitation attempts. This requires the cs(Cookie) field in W3C logging. SPL: index=iis sc_status=404 cs_cookie="*DNNPersonalization=*" | stats count by c_ip
      • Sysmon EID 1 / EDR: Process ancestry w3wp.exe → cmd.exe/powershell.exe/whoami.exe. KQL: DeviceProcessEvents | where InitiatingProcessFileName =~ "w3wp.exe" and FileName in~ ("cmd.exe","powershell.exe","whoami.exe","certutil.exe")
      • Sysmon EID 11: w3wp.exe writing .aspx, .ashx or .asmx files into the DNN webroot points to webshell drops (Sigma: category: file_event, Image|endswith: '\w3wp.exe', TargetFilename|endswith: '.aspx').
      • Registration and reset abuse: Many sign-ups or password-reset requests from one source (/Register, ?ctl=Register, ?ctl=SendPassword). This pattern suggests attackers harvesting verification codes to use as a crypto oracle.
      • Zeek/Suricata: New outbound connections from the web server to external hosts shortly after suspicious requests carrying the cookie.

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    DNN (aka DotNetNuke) 9.2 through 9.2.2 uses a weak encryption algorithm to protect input parameters. NOTE: this issue exists because of an incomplete fix for CVE-2018-15811.

    Source: NVD (NIST), OSV (Open Source Vulnerabilities), cvelistv5, CISA KEV Catalog

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    dnnsoftwaredotnetnuke
    • 9.2 – ≤ 9.2.2
    • —
    nugetdotnetnuke.core
    • 9.2.0.366
    • 9.2.1.533
    • 9.1.1.129
    • 8.0.2.4
    • 7.4.1.280
    • 7.1.0
    • 6.0.0
    • 9.0.1.142
    • 7.0.0
    • 8.0.1.239
    • 7.3.0.499
    • 8.0.3.5
    • 9.1.0.367
    • 7.3.1.20
    • 7.0.6.121
    • 7.4.0.353
    • 9.0.0.1002
    • 8.0.4.226
    • 7.4.2.216
    • 8.0.0.809
    • 7.1.2
    • 7.2.0.613
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    Vendors and products

    Weakness classes (CWE)

    • CWE-326Inadequate Encryption Strength

      Class

      The product stores or transmits sensitive data using an encryption scheme that is theoretically sound, but is not strong enough for the level of protection required.

      Entry at MITRE CWE-326

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited
    Packet StormDotNetNuke Cookie Deserialization Remote Code Execution (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—

    References & sources

    • NVD (NIST)vuln/detail/CVE-2018-18325advisory
    • github.comdnnsoftware/Dnn.Platformpackage
    • github.comdnnsoftware/Dnn.Platform/releasesweb, x_refsource_MISC, Release notes
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2018-18325web, government-resource, US government resource
    • dnnsoftware.comcommunity/security/security-centerweb, x_refsource_MISC, Vendor advisory
    • packetstormsecurity.comfiles/157080/DotNetNuke-Cookie-Deserialization-Remote-Code-Exec…web, x_refsource_MISC, Exploit, Third-party advisory, Vulnerability database
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