CriticalCVE-2025-2749

    Kentico Xperience <= 13.0.178 Staging Media File Upload Authenticated RCE (CVE-2025-2749)

    Published In CISA KEV since Sources: CVE.org

    What is affected, what to do

    An authenticated remote code execution in Kentico Xperience allows authenticated users Staging Sync Server to upload arbitrary data to path relative locations. This results in path traversal and arbitrary file upload, including content that can be executed server side leading to remote code execution.This issue affects Kentico Xperience through 13.0.178.

    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

    7.2

    Priority

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

    Source: NVD, CVSS v3

    7.2

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: CVE.org

    4.0 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 90.5

    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
    209.89 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
    7.2 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
    7.2
    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“.

    Read in glossary
    4.0 %
    Moderate — model estimates 1-10% exploitation likelihood.
    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
    90.5
    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-22, CWE-434

    Response and mitigation

    Why act now?

    Prioritisation rationale

    The flaw is network-reachable, needs no user interaction and yields full code execution on the web server. The high-privilege requirement matters less than it looks, because staging credentials are often weak or shared, or can be bypassed through the known authentication flaws in the same service. Attackers typically chain these issues to drop webshells on internet-facing CMS deployments, mainly corporate and public-sector portals and e-commerce sites. Exploitation likelihood is well above average; CISA lists no known ransomware use. If the staging endpoint is internet-reachable, treat this as critical and patch within 24 h. If staging is disabled or strictly IP-restricted, an accelerated regular patch cycle is sufficient.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory: Find every Kentico Xperience 13 instance, including dev, staging and production. All versions up to and including 13.0.178 are affected. Check the version in the admin UI under "System" or in the hotfix directory.
      • Apply the hotfix: Install a Kentico hotfix later than 13.0.178. A patch is available from the vendor; look up the exact target version in the Kentico vendor advisory or hotfix release notes. Patch every server in the staging topology so source and target stay version-consistent.
      • Disable the staging service: Where content staging isn't strictly required, turn it off now via Settings → Versioning & Synchronization → Staging → untick "Enable staging service". Also block /CMSPages/Staging/SyncServer.asmx at the reverse proxy or in IIS.
      • Rotate credentials: Rotate the staging-service credentials (username/password or X.509 certificates) on all source and target servers. Review and rotate global administrator and service accounts as well. Exploitation needs high privileges, so stolen staging credentials are all an attacker needs.
      • Hunt for compromise: On exposed instances, sweep the web root for .aspx, .ashx, .asmx, .config and .dll files created or modified since the vulnerable version went live. If you find anything, isolate the host and preserve evidence before cleaning up.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: Allow access to SyncServer.asmx only from the designated staging source server. Use IIS "IP Address and Domain Restrictions" or a firewall/reverse-proxy ACL. The endpoint must never be reachable from the internet.
      • WAF/IPS: Block POST requests to /CMSPages/Staging/ whose SOAP body contains traversal sequences (../, ..\, %2e%2e%2f, %2e%2e%5c). Also reject staging payloads with executable filename extensions (.aspx, .ashx, .config).
      • Endpoint hardening: Limit the IIS application-pool identity to write access on directories that genuinely need it (media library, App_Data). Deny write access to the application root, bin\ and web.config. Remove script handlers from upload directories via web.config.
      • IAM / least privilege: Move staging authentication from username/password to X.509 certificates where feasible, with unique, strong credentials per environment. Previously disclosed staging authentication weaknesses (CVE-2025-2746, CVE-2025-2747) can effectively remove the high-privilege barrier, so patch those too.
      • Application control: Use EDR or AppLocker/WDAC to block, or at least alert on, w3wp.exe spawning cmd.exe, powershell.exe, certutil.exe or rundll32.exe.

    3. Runbook step 3

      Detection rules

      • IIS access logs: Flag POSTs to /CMSPages/Staging/SyncServer.asmx from any IP other than the known staging source. Example (KQL, W3CIISLog): W3CIISLog | where csUriStem has "/CMSPages/Staging/SyncServer.asmx" and csMethod == "POST" and cIP !in (staging_src_ips)
      • Sysmon EID 11 (FileCreate): Flag w3wp.exe writing executable web files outside expected paths. Sigma shape: Image|endswith: '\w3wp.exe' AND TargetFilename|endswith: ['.aspx','.ashx','.asmx','.config','.dll'] AND NOT TargetFilename|contains: '\App_Data\'.
      • Process ancestry (Sysmon EID 1 / Security 4688): w3wp.exe spawning cmd.exe, powershell.exe, whoami.exe or net.exe points to a webshell being used after a successful upload. SPL: index=sysmon EventCode=1 ParentImage="*\\w3wp.exe" Image IN ("*\\cmd.exe","*\\powershell.exe","*\\whoami.exe")
      • Kentico event log: In CMS_EventLog, look for staging events that don't match any scheduled sync task. Also watch for staging authentication failures followed by a success, which suggests credential guessing.
      • Network (Zeek/Suricata): Watch for unusually large SOAP requests to the staging endpoint. Also flag new outbound connections from the web server to unfamiliar destinations shortly after staging calls.

    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 authenticated remote code execution in Kentico Xperience allows authenticated users Staging Sync Server to upload arbitrary data to path relative locations. This results in path traversal and arbitrary file upload, including content that can be executed server side leading to remote code execution.This issue affects Kentico Xperience through 13.0.178.

    Source: 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-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

      Base

      The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

      Entry at MITRE CWE-22

    • CWE-434Unrestricted Upload of File with Dangerous Type

      Base

      The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.

      Entry at MITRE CWE-434

    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 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.comdownload/hotfixesVendor advisory, Patch, Patch
    • vulncheck.comadvisories/kentico-xperience-staging-media-file-upload-authenti…Third-party advisory, Third-party advisory
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2025-2749government-resource, US government resource

    Linked advisories

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    Badge preview for CVE-2025-2749
    <a href="https://intel.neosec.eu/en/cve/CVE-2025-2749"><img src="https://intel.neosec.eu/badge/cve/CVE-2025-2749.svg?lang=en" alt="CVE-2025-2749 – NEOSEC Intel" height="20"></a>