CriticalCVE-2025-2747

    Kentico Xperience <= 13.0.178 Staging Sync Server None Password Type Authentication Bypass (CVE-2025-2747)

    Published In CISA KEV since Sources: pwn.watch, CVE.org

    What is affected, what to do

    An authentication bypass vulnerability in Kentico Xperience CMS allows an attacker to control administrative objects by exploiting an alternate path or channel. This issue affects versions up to 13.0.178 and is actively exploited in the wild. The vulnerability involves password handling in the Staging Sync Server component for the server type None. It is critical to update to the latest version to mitigate this security risk.

    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
    • Kentico Xperience lte *..13.0.178

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

    Metrics

    9.8

    Priority

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

    Source: NVD, CVSS v3

    9.8

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: pwn.watch, CVE.org

    97.2 %

    EPSS score

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

    Source: FIRST EPSS, percentile 99.89

    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
    237.16 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.

    Read in glossary
    actively exploitedSource: VulnCheck KEV (opens in a new tab) How we classify
    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
    9.8 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
    9.8
    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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    97.2 %
    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
    99.89
    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
    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-288

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This flaw is reachable over the network with no authentication and no user interaction, and it gives the attacker full control of administrative CMS objects. Public research describes a chain with other Kentico flaws that leads to code execution, which places this CVE among those most likely to be exploited of any vulnerability. Typical targets are public-facing corporate and public-sector sites on Kentico Xperience 13, where compromise enables defacement, malware delivery to visitors and pivoting into the internal network. CISA has not flagged ransomware use. Even so, treat any internet-exposed instance with the staging service enabled as top priority and remediate within 24 h. Internal-only instances with staging disabled can follow your standard emergency patch window.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory: Enumerate every Kentico Xperience 13 instance (prod, staging, dev) and check its hotfix level (admin UI → System, or CMSHotfixVersion). Everything up to and including 13.0.178 is vulnerable.
      • Patch: Apply the Kentico hotfix that brings you to a version later than 13.0.178. Patch available from the vendor — look up the exact version in the vendor advisory. Patch internet-facing instances first.
      • Turn off the staging service where unused: Go to Settings → Versioning & Synchronization → Staging and disable "Enable staging service". With the service off, the vulnerable endpoint cannot be reached.
      • Block the endpoint now: Deny /CMSPages/Staging/SyncServer.asmx at the reverse proxy, load balancer or WAF for every source except your known staging source servers (return 403).
      • Compromise assessment: Review IIS logs back to late March 2025 for hits on SyncServer.asmx. If any come from unknown IPs, isolate the host and take a forensic image. Then rotate all CMS admin credentials, database connection strings and machine keys.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: Restrict staging sync traffic to defined source and target servers only, using a dedicated management VLAN or an IIS IP allowlist (<ipSecurity allowUnlisted="false"> scoped to /CMSPages/Staging/). Never expose the endpoint to the internet.
      • Authentication type: If staging is business-critical, switch server authentication from username/password to X.509 certificates. This removes the vulnerable password-handling path. Also set a long, random staging password.
      • WAF/IPS: Drop POSTs to SyncServer.asmx carrying a wsse:UsernameToken SOAP header from non-allowlisted sources. In Suricata, match http.uri on /cmspages/staging/syncserver.asmx with a negated source-IP set for the staging servers.
      • Endpoint hardening: Run the IIS app pool under a low-privilege identity, never LocalSystem. Limit the app pool account's write access in the web root to the directories it actually needs (e.g. App_Data, media library) so webshells are harder to drop.
      • Least privilege: Reduce the number of Global Administrator accounts. Do not run the CMS database login as db_owner/sysadmin at server scope.

    3. Runbook step 3

      Detection rules

      • IIS access logs: Alert on any POST /CMSPages/Staging/SyncServer.asmx from a non-staging IP. Example SPL: index=iis cs_uri_stem="*/CMSPages/Staging/SyncServer.asmx" cs_method=POST NOT c_ip IN (<staging_ips>) | stats count by c_ip, sc_status
      • Kentico event log: Query CMS_EventLog (or the Event log app) for staging tasks (source "Staging"), new user creation, role changes to Global Administrator, and media file or page template edits with no matching change ticket.
      • Sysmon EID 11 / EDR: Look for new .aspx, .ashx, .asmx or .config files written into the web root by w3wp.exe. Sigma shape: Image|endswith: '\w3wp.exe' AND TargetFilename|endswith: ['.aspx','.ashx']
      • Sysmon EID 1 / process ancestry: Watch for w3wp.exe spawning cmd.exe, powershell.exe, whoami.exe or certutil.exe. This chain is a strong signal of post-exploitation (webshell or RCE after admin takeover). Example KQL: DeviceProcessEvents | where InitiatingProcessFileName =~ "w3wp.exe" and FileName in~ ("cmd.exe","powershell.exe","whoami.exe")
      • Network telemetry (Zeek): Correlate new outbound connections from the web server with preceding SyncServer.asmx requests.

    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

    An authentication bypass vulnerability in Kentico Xperience allows authentication bypass via the Staging Sync Server component password handling for the server defined None type. Authentication bypass allows an attacker to control administrative objects.This issue affects Xperience through 13.0.178.

    Source: pwn.watch, NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)

    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
    KenticoXperience
    • ≤ 13.0.178
    • —
    kenticoxperience
    • ≤ 13.0.178
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-288Authentication Bypass Using an Alternate Path or Channel

      Base

      The product requires authentication, but the product has an alternate path or channel that does not require authentication.

      Entry at MITRE CWE-288

    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
    Reference tagged as exploitgithub.com (opens in a new tab)PoC (publicly reported)reported, not verified—
    Reference tagged as exploitlabs.watchtowr.com (opens in a new tab)PoC (publicly reported)reported, not verified—

    References & sources

    • labs.watchtowr.combypassing-authentication-like-its-the-90s-pre-auth-rce-chain-s-…Technical description, Exploit, Exploit, Third-party advisory
    • devnet.kentico.comKentico advisory: Kentico Xperience CMSVendor advisory, Patch, Patch, pwn-watch
    • github.comwatchtowrlabs/kentico-xperience13-AuthBypass-wt-2025-0011Exploit, Third-party advisory
    • vulncheck.comadvisories/kentico-xperience-staging-sync-server-none-password-…Third-party advisory, Third-party advisory
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2025-2747government-resource, US government resource
    • pwn.watchpwn.watch: Kentico Xperience CMS: 2 exploited vulnerabilities (CVE-2025-2746, CVE-2025-2747)pwn-watch
    • NVD (NIST)NVD: CVE-2025-2746pwn-watch
    • NVD (NIST)NVD: CVE-2025-2747pwn-watch
    • cisa.govCISA Known Exploited Vulnerabilities Catalogpwn-watch
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