CriticalCVE-2025-8875

    Insecure Deserialization Vulnerability (CVE-2025-8875)

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

    What is affected, what to do

    Deserialization of Untrusted Data vulnerability in N-able N-central allows Local Execution of Code.This issue affects N-central: before 2025.3.1.

    The vulnerability is being actively exploited; treat it as a priority. Update N-able N-central to version 2025.3.1. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • N-able N-central lt *..2025.3.1
    Fixed in
    • N-able N-central 2025.3.1

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

    Metrics

    9.4

    Priority

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

    Source: NVD, CVSS v4

    7.8

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: pwn.watch, CVE.org

    2.5 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 84.8

    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
    214.84 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 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.

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    9.4 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
    7.8
    CVSS v4

    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
    9.4
    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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    2.5 %
    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.

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    84.8
    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.

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    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.

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    CISA assessment (SSVC)
    Exploitation: active · not automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 14 August 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-502

    Response and mitigation

    Why act now?

    Prioritisation rationale

    N-central is an RMM platform with privileged reach into potentially thousands of managed endpoints. Whoever controls the server can push code across every customer or site, which is why attackers deliberately target RMM tooling, particularly at MSPs as a gateway into many organisations at once. The flaw needs low-privileged local access, but it then yields full loss of confidentiality, integrity and availability. That makes it an ideal second stage after initial access via stolen accounts or a chained bug. Exploitation likelihood is elevated, and CISA currently records no ransomware use. If you run N-central or are managed through it, treat the upgrade as critical and complete it within 24–72 hours, regardless of the nominally "local" attack vector.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Patch now: Upgrade every N-central server to version 2025.3.1 or later. All releases before 2025.3.1 are affected. Verify on-prem and hosted instances separately, and get written confirmation of patch status from N-able for hosted tenants.
      • Inventory: Enumerate all N-central instances, including lab, staging and MSP-operated ones. Record the running version from the admin UI or the appliance. Under NIS2 supply-chain obligations, ask your MSP in writing whether they run N-central against your estate.
      • Restrict local access: Exploitation requires low-privileged local access. Audit all local and SSH accounts on the N-central host immediately. Disable anything unneeded and restrict SSH to a dedicated admin jump host.
      • Rotate secrets: Rotate N-central admin accounts, API tokens and stored domain or service credentials if you suspect compromise or the instance sat unpatched and exposed. This covers credentials used by probes, scripts and automation policies. An RMM server is effectively a credential vault.
      • Preserve evidence before patching: Capture logs, the process list and recently modified files before the upgrade overwrites artefacts. This includes web server, Tomcat/Java and system logs plus shell history.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: Place the N-central server in a dedicated management zone. Expose the admin UI only to the admin network or via MFA-protected VPN, never directly to the internet. Leave only agent communication externally reachable, and only where strictly required.
      • Egress control: Allowlist outbound traffic from the server to required destinations only: vendor update endpoints, the mail relay and agent networks. Block arbitrary outbound connections, especially on non-standard ports and patterns typical of reverse shells.
      • Least privilege: Minimise shell accounts on the appliance. Apply least-privilege roles in the N-central UI. Restrict the ability to push scripts or automation policies to a small, MFA-enforced admin group.
      • Host hardening: Mount /tmp and /var/tmp with noexec where supported. Enable file-integrity monitoring (AIDE, Wazuh FIM) on the application directories.
      • Downstream endpoint control: A compromised RMM behaves like a supply-chain attack. Review and narrow any blanket EDR exclusions for the RMM agent on managed endpoints, so its child processes are still inspected.

    3. Runbook step 3

      Detection rules

      • Linux process ancestry (auditd/EDR): The N-central Java or Tomcat process spawns shells or downloaders. Sigma shape: ParentImage|endswith: '/java' AND Image|endswith: ['/sh','/bash','/curl','/wget','/nc','/python3'].
      • auditd exec events: type=EXECVE under the application service UID with suspicious arguments such as base64 -d, chmod +x or /dev/tcp/. Also watch for new executable files dropped into /tmp.
      • Authentication and local access: Look for unusual SSH logons to the N-central host (/var/log/secure, sshd events), especially from non-admin source IPs. Treat follow-on privilege activity shortly afterwards as high-signal: sudo use, new entries in /etc/passwd, or authorized_keys modifications.
      • Network telemetry (Zeek/Suricata): Alert on outbound connections from the N-central server to previously unseen external IPs, as deviations from baseline. KQL shape: CommonSecurityLog | where SourceIP == "<ncentral_ip>" and DestinationIP !in (allowlist).
      • Managed endpoints (Sysmon EID 1 / Event ID 4688): The RMM agent spawns powershell.exe, cmd.exe or rundll32.exe with encoded commands outside maintenance windows. Reconcile newly created scripts and automation policies in the N-central audit log against change tickets.

    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

    Deserialization of Untrusted Data vulnerability in N-able N-central allows Local Execution of Code.This issue affects N-central: before 2025.3.1.

    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
    N-ableN-central
    • < 2025.3.1
    • 2025.3.1
    n-ablen-central
    • < 2025.3.1
    • 2025.3.1

    Vendors and products

    Weakness classes (CWE)

    • CWE-502Deserialization of Untrusted Data

      Base

      The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

      Entry at MITRE CWE-502

    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

    References & sources

    • status.n-able.comN-able advisory: N-able N-Centralpwn-watch
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2025-8875government-resource
    • pwn.watchpwn.watch: N-able N-Central: 2 exploited vulnerabilities (CVE-2025-8875, CVE-2025-8876)pwn-watch
    • NVD (NIST)NVD: CVE-2025-8875pwn-watch
    • NVD (NIST)NVD: CVE-2025-8876pwn-watch
    • cisa.govCISA Known Exploited Vulnerabilities Catalogpwn-watch

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    One NVD translation into another language is hidden.

    Linked advisories

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