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CVE-2019-17558 Apache CVE debrief

CVE-2019-17558 is a remote code execution vulnerability in Apache Solr’s VelocityResponseWriter plug-in. CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03, which indicates it has been observed as actively exploited and should be treated as a high-priority remediation item.

Vendor
Apache
Product
Solr
CVSS
Unknown
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

Apache Solr operators, especially teams running deployments that use or expose the VelocityResponseWriter plug-in, should prioritize this advisory. Security and platform teams responsible for internet-facing search infrastructure should also review exposure and patch status.

Technical summary

The vulnerability affects Apache Solr’s VelocityResponseWriter plug-in and enables remote code execution. CISA’s KEV entry confirms the issue is considered known exploited. The source corpus does not provide exploit mechanics, affected version ranges, or specific attacker tradecraft, so defensive attention should focus on exposure assessment and remediation per vendor guidance.

Defensive priority

High. CISA KEV inclusion means this vulnerability should be remediated as soon as possible, with priority given to externally reachable Solr instances and any environment using the affected plug-in path.

Recommended defensive actions

  • Apply updates per vendor instructions.
  • Inventory Apache Solr deployments and determine whether VelocityResponseWriter is enabled or reachable.
  • Reduce network exposure for Solr where possible, especially on internet-facing systems.
  • Review access controls and monitoring around Solr endpoints for unusual or unexpected requests.
  • Validate remediation against the official Apache and CISA guidance before returning affected services to production.

Evidence notes

This debrief is based on the supplied CISA KEV source item and official reference links. The corpus confirms the CVE title, Apache Solr product association, KEV inclusion, dateAdded of 2021-11-03, dueDate of 2022-05-03, and the required action to apply updates per vendor instructions. No version ranges, exploit details, or additional technical specifics were used beyond the supplied corpus and official links.

Sources and references

Verified primary and authoritative sources

  • CVE-2019-17558 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2019-17558

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

  • CVE-2019-17558 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2019-17558

    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.