CriticalCVE-2019-11580

    Atlassian Crowd and Crowd Data Center Remote Code Execution Vulnerability (CVE-2019-11580)

    Published In CISA KEV since Sources: CVE.org

    What is affected, what to do

    An unauthenticated attacker can gain full control of a Crowd or Crowd Data Center instance through remote code execution (RCE) by exploiting the incorrectly enabled pdkinstall development plugin. This vulnerability is actively exploited in ransomware campaigns since 2021. Affected versions include Crowd from 2.1.0 to 3.0.5, 3.1.0 to 3.1.6, 3.2.0 to 3.2.8, 3.3.0 to 3.3.5, and 3.4.0 to 3.4.4. Immediate patching to the respective fixed versions is critical to mitigate this vulnerability.

    The vulnerability is being actively exploited; treat it as a priority. CISA lists it as used in ransomware campaigns. Update Atlassian Crowd to version 3.0.5, Atlassian Crowd to version 3.1.6, Atlassian Crowd to version 3.2.8. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Atlassian Crowd eq 2.1.0..2.1.0
    • Atlassian Crowd lt *..3.0.5
    • Atlassian Crowd eq 3.1.0..3.1.0
    • Atlassian Crowd lt *..3.1.6
    • Atlassian Crowd eq 3.2.0..3.2.0
    • Atlassian Crowd lt *..3.2.8
    • Atlassian Crowd eq 3.3.0..3.3.0
    • Atlassian Crowd lt *..3.3.5
    • Atlassian Crowd eq 3.4.0..3.4.0
    • Atlassian Crowd lt *..3.4.4
    Fixed in
    • Atlassian Crowd 3.0.5
    • Atlassian Crowd 3.1.6
    • Atlassian Crowd 3.2.8
    • Atlassian Crowd 3.3.5
    • Atlassian Crowd 3.4.4

    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

    95.4 %

    EPSS score

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

    Source: FIRST EPSS, percentile 99.87

    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
    253.79 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“.

    Read in glossary
    95.4 %
    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
    99.87
    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 7 February 2025

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This CVE sits on KEV because pdkinstall hands an unauthenticated attacker a trivial path to remote code execution as the Crowd service user — weaponised exploits have been in Metasploit and public scanners since 2019. CISA flags active ransomware use, and Crowd is a tier-one pivot target: a successful compromise unlocks the entire Atlassian toolchain (Jira, Confluence, Bitbucket) through its SSO / identity-broker role. For NIS2-scoped organisations running an internet-reachable Crowd instance, treat this as a P1 patch: network-reachable without authentication, among the most likely CVEs to be exploited, and a blast radius spanning the engineering stack. Internally reachable instances remain P2 due to insider and lateral-movement scenarios.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Upgrade Atlassian Crowd / Crowd Data Center to a fixed release: 3.0.5, 3.1.6, 3.2.8, 3.3.5 or 3.4.4 (or later). The 2.1.x branch is end-of-life — plan migration to a supported branch.
      • If immediate patching is impossible, disable the pdkinstall plugin and ensure /crowd/admin/uploadplugin.action returns 403 via a reverse-proxy rule. Verify through crowd-webapp/WEB-INF/classes/crowd-init.properties and the plugin manager that no development plugin is active in production.
      • Restrict network access to the Crowd admin UI to a management VLAN / jump host; remove TCP/8095 (default) and the proxy-fronted port from internet and user-segment exposure.
      • Compromise check BEFORE patching: compare <crowd-home>/plugins/ and shared/plugins/ against the vendor-shipped JAR list, flag any file created after 1 May 2019; review process history of the Crowd service account (typically crowd or atlassian) for shell spawns.
      • Rotate every credential stored in crowd.cfg.xml, Application Links and JDBC connection strings — treat them as compromised whenever exploitation cannot be ruled out. Invalidate SSO / delegated-auth tokens for all downstream applications federated through Crowd (Jira, Confluence, Bitbucket).
      • Pre-triage the incident against NIS2 Article 23 reporting duties; prepare the 24-hour early-warning notification to the national CSIRT if active exploitation is suspected.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: expose Crowd only behind a reverse proxy (nginx, Apache, F5) with a path allowlist (/crowd/console/, /crowd/rest/usermanagement/, /crowd/plugins/servlet/); return 403 for everything under /crowd/admin/uploadplugin* and /crowd/plugins/servlet/upm.
      • WAF / IPS rule: drop HTTP POST with Content-Type: multipart/form-data targeting uploadplugin.action; add a generic signature for JAR magic bytes (PK\x03\x04) combined with a .jar filename in request bodies. Suricata shape: alert http any any -> $CROWD_SERVERS any (msg:"CVE-2019-11580 Crowd pdkinstall upload"; http.uri; content:"uploadplugin.action"; nocase; sid:XXXXXXX;).
      • Endpoint hardening: run the Crowd service user with no shell / no sudo, apply an AppArmor or SELinux profile that limits writes to <crowd-home> and logs/, and constrain outbound connections of the Java process via host firewall to DB, mail and the SSO IdP — no general internet egress.
      • IAM hardening: reduce the Crowd administrator role to named accounts with FIDO2/MFA, separate API-only service accounts from interactive ones, and audit the crowd-administrators group membership.
      • Configuration: explicitly disable development / debug plugins (pdkinstall, dev-mode webresource plugins) in production, and verify the deployed Crowd WAR checksum against the vendor-published hash.

    3. Runbook step 3

      Detection rules

      • Reverse-proxy / Tomcat access logs: any request against *uploadplugin.action* in production is a hit. KQL shape: WebLogs | where cs_uri_stem has "uploadplugin.action" | project TimeGenerated, c_ip, cs_method, sc_status, cs_user_agent.
      • Process telemetry (Sysmon EID 1 / auditd execve): child processes of the Java runtime invoking sh, bash, cmd.exe, powershell.exe, curl, wget, nc, python. Sigma shape: parent_image|endswith: 'java' AND CommandLine|contains: ['/tmp/','base64','curl','wget'].
      • Filesystem monitoring (Sysmon EID 11, auditd watches): new .jar files landing in <crowd-home>/plugins/, shared/plugins/ or temp/plugins/ outside approved change windows.
      • Network telemetry (Zeek conn.log / http.log): egress connections from the Crowd host to non-infrastructure destinations — Tor exits, known webshell C2 domains, raw-IP paste services. Baseline: Crowd legitimately talks only to DB, LDAP/AD, SMTP and the Atlassian licence endpoint.
      • Crowd application log (atlassian-crowd.log): stack traces containing com.atlassian.plugin.manager or UploadPluginAction for an unauthenticated session are high-fidelity exploit-attempt IOCs.

    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

    Atlassian Crowd and Crowd Data Center had the pdkinstall development plugin incorrectly enabled in release builds. Attackers who can send unauthenticated or authenticated requests to a Crowd or Crowd Data Center instance can exploit this vulnerability to install arbitrary plugins, which permits remote code execution on systems running a vulnerable version of Crowd or Crowd Data Center. All versions of Crowd from version 2.1.0 before 3.0.5 (the fixed version for 3.0.x), from version 3.1.0 before 3.1.6 (the fixed version for 3.1.x), from version 3.2.0 before 3.2.8 (the fixed version for 3.2.x), from version 3.3.0 before 3.3.5 (the fixed version for 3.3.x), and from version 3.4.0 before 3.4.4 (the fixed version for 3.4.x) are affected by this vulnerability.

    Source: NVD (NIST), 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
    AtlassianCrowd
    • 3.3.0
    • 3.4.0
    • < 3.3.5
    • < 3.1.6
    • 3.2.0
    • 2.1.0
    • < 3.4.4
    • < 3.2.8
    • < 3.0.5
    • 3.1.0
    • —
    • —
    • 3.3.5
    • 3.1.6
    • —
    • —
    • 3.4.4
    • 3.2.8
    • 3.0.5
    • —
    atlassiancrowd
    • 3.3.0 – < 3.3.5
    • 2.1.0 – < 3.0.5
    • 3.1.0 – < 3.1.6
    • 3.2.0 – < 3.2.8
    • 3.4.0 – < 3.4.4
    • 3.3.5
    • 3.0.5
    • 3.1.6
    • 3.2.8
    • 3.4.4

    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
    Packet StormAtlassian Crowd pdkinstall Remote Code Execution (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—

    References & sources

    • jira.atlassian.combrowse/CWD-5388x_refsource_MISC, Issue tracking, Mitigation, Vendor advisory
    • securityfocus.com108637Vulnerability database, x_refsource_BID, Broken link
    • packetstormsecurity.comfiles/163810/Atlassian-Crowd-pdkinstall-Remote-Code-Execution.h…x_refsource_MISC, Exploit, Third-party advisory, Vulnerability database
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2019-11580government-resource, US government resource
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