CriticalCVE-2019-7238

    Sonatype Nexus Repository Manager Incorrect Access Control Vulnerability (CVE-2019-7238)

    Published In CISA KEV since Sources: CVE.org

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    What is affected, what to do

    Sonatype Nexus Repository Manager before 3.15.0 has Incorrect Access Control.

    The vulnerability is being actively exploited; treat it as a priority. Update Sonatype Nexus Repository 3 to version 3.15.0. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Sonatype Nexus Repository 3 lt 3.0.0..3.15.0
    Fixed in
    • Sonatype Nexus Repository 3 3.15.0

    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: CVE.org

    76.6 %

    EPSS score

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

    Source: FIRST EPSS, percentile 99.54

    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
    228.27 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 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
    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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    76.6 %
    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
    99.54
    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: total
    Source: CISA Vulnrichment, as of 4 February 2025

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This flaw gives an unauthenticated attacker remote code execution over the network through JEXL expression injection, with no user interaction required. Public exploits have circulated for years, and it sits among the CVEs most likely to be exploited. It has been hit by mass, automated scanning, mainly by cryptomining botnets and as a foothold into build environments; CISA does not flag ransomware use. Nexus concentrates credentials, deploy tokens and software artifacts, so a compromise is a direct supply-chain incident with NIS2 relevance. Treat internet-facing instances below 3.15.0 as critical and act immediately; treat internal, segmented instances as high and upgrade within days.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Find exposed instances: Inventory every Sonatype Nexus Repository Manager 3.x instance (default port 8081/tcp, often fronted by a reverse proxy on 443). Internet-reachable instances come first.
      • Upgrade: Move to Nexus Repository Manager 3.15.0 or later. Prefer the current supported 3.x release, because later Nexus versions fixed further RCE flaws. Check the vendor advisory for the exact target version.
      • Emergency isolation if you cannot upgrade today: Firewall port 8081 and the reverse proxy so that only build servers, CI/CD runners and the admin network can reach them. Remove all internet exposure.
      • Compromise check before upgrading: Grep sonatype-work/nexus3/log/request.log for POSTs to /service/extdirect that contain previewAssets and jexlExpression. Also hunt for child processes of the Nexus JVM, new cron jobs owned by the service account, and unknown admin users or scripts (Scripting API).
      • Rotate secrets if compromise is suspected: Reset admin passwords, the LDAP bind account, upstream proxy credentials, deploy tokens and user tokens. Verify the integrity of stored artifacts, especially in hosted repositories, because this is a supply-chain risk.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: Place Nexus in a dedicated build/artifact segment. Allow ingress only from CI/CD and developer VLANs. Restrict egress to an allowlist of required upstream registries (e.g. Maven Central, the npm registry). Block arbitrary outbound traffic and mining-pool Stratum ports.
      • Reverse proxy / WAF rule: Drop POSTs to /service/extdirect whose body contains jexlExpression together with getClass, forName, java.lang.Runtime, ProcessBuilder or exec. The Nexus UI uses extdirect legitimately, so filter on body content rather than blocking the whole path.
      • IPS signature (Suricata/Snort): alert http any any -> $NEXUS 8081 (msg:"CVE-2019-7238 Nexus JEXL RCE"; flow:to_server; http.method; content:"POST"; http.uri; content:"/service/extdirect"; http.request_body; content:"previewAssets"; content:"jexlExpression"; sid:...;). Enable any existing ET rules for CVE-2019-7238.
      • Endpoint/container hardening: Run Nexus under an unprivileged service account, never as root. In containers, use a read-only root filesystem and ship no curl or wget in the image. Use AppArmor/SELinux to stop the JVM from spawning shells.
      • IAM/least privilege: Disable anonymous access where operationally feasible. This shrinks the attack surface but does not replace the upgrade. Keep admin-role membership to a minimum and disable the Scripting API.

    3. Runbook step 3

      Detection rules

      • Web server / Nexus request log: POSTs to /service/extdirect whose body contains "method":"previewAssets" and a jexlExpression with Java reflection patterns. SPL: index=web uri_path="/service/extdirect" method=POST | search "jexlExpression" ("getClass" OR "Runtime" OR "exec").
      • EDR process ancestry (Linux): java running as the Nexus account spawns sh, bash, curl, wget, python or perl. auditd: -a always,exit -F arch=b64 -S execve -F uid=<nexus-uid> -k nexus_exec. Treat any hit outside known maintenance work as critical.
      • Sysmon EID 1 (Windows): ParentImage ends in \java.exe (Nexus install path) and Image is cmd.exe, powershell.exe, certutil.exe or bitsadmin.exe. KQL: DeviceProcessEvents | where InitiatingProcessFileName =~ "java.exe" and InitiatingProcessFolderPath has "nexus" and FileName in~ ("cmd.exe","powershell.exe","certutil.exe").
      • Network telemetry (Zeek/Suricata): Outbound connections from the Nexus host to unfamiliar IPs, Stratum traffic (mining.subscribe), or downloads of shell scripts and ELF binaries shortly after extdirect POSTs.
      • Persistence: New crontab entries, or files in /tmp and /var/tmp owned by the Nexus account. Also look for new admin users and scripts in the Nexus audit log.

    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

    Sonatype Nexus Repository Manager before 3.15.0 has Incorrect Access Control.

    Source: cvelistv5, CISA KEV Catalog, NVD (NIST)

    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
    sonatypenexus_repository_manager
    • 3.0.0 – < 3.15.0
    • 3.15.0

    Vendors and products

    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
    PoC-in-GitHub (nomi-sec)vulhub-nexus-cve-2019-7238 (opens in a new tab)github.comPoC (publicly reported)reported, not verified

    References & sources

    • support.sonatype.comhc/en-us/articles/360017310793-CVE-2019-7238-Nexus-Repository-M…x_refsource_MISC
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2019-7238government-resource
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