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CVE-2019-11634 Citrix CVE debrief

CVE-2019-11634 is a Citrix Workspace Application and Receiver for Windows remote code execution vulnerability that CISA lists in its Known Exploited Vulnerabilities catalog. The KEV record indicates known ransomware campaign use, so this issue should be treated as a high-priority remediation item for any environment still running the affected Citrix client software.

Vendor
Citrix
Product
Workspace Application and Receiver for Windows
CVSS
CRITICAL 9.8
CISA KEV
Listed
Original CVE published
2021-11-03
Original CVE updated
2021-11-03
Advisory published
2021-11-03
Advisory updated
2021-11-03

Who should care

IT and security teams managing Citrix Workspace Application or Receiver for Windows installations, especially endpoint management, vulnerability management, and SOC teams responsible for prioritizing KEV items.

Technical summary

The supplied sources identify this as a remote code execution vulnerability affecting Citrix Workspace Application and Receiver for Windows. The CISA KEV entry marks it as a known exploited vulnerability and notes known ransomware campaign use. No further technical detail is included in the provided corpus, so remediation should be driven by the vendor update guidance referenced by CISA.

Defensive priority

Urgent. CISA has added this CVE to the Known Exploited Vulnerabilities catalog and marked it as used in known ransomware campaigns, which elevates remediation priority beyond routine patching.

Recommended defensive actions

  • Apply updates per the vendor's instructions for Citrix Workspace Application and Receiver for Windows.
  • Inventory endpoints and virtual desktops to identify any installed Citrix Workspace Application or Receiver for Windows instances.
  • Prioritize remediation of internet-connected, user-facing, and high-value endpoints first.
  • Track this CVE as a KEV item in vulnerability management workflows until all affected systems are confirmed updated.
  • Validate that remediation is complete using post-patch inventory and compliance checks.

Evidence notes

This debrief is based only on the supplied CISA KEV source item and official links. The source item states: vendorProject Citrix; product Workspace Application and Receiver for Windows; vulnerability name 'Citrix Workspace Application and Receiver for Windows Remote Code Execution Vulnerability'; dateAdded 2021-11-03; dueDate 2022-05-03; knownRansomwareCampaignUse Known; requiredAction 'Apply updates per vendor instructions.' The NVD and CVE.org links were provided as official reference points, but no additional technical details from those pages were supplied in the corpus.

Sources and references

Verified primary and authoritative sources

  • CVE-2019-11634 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2019-11634

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2019-11634 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2019-11634

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.