VulnSocial

CVE-2021-23017Disclosure(f5 / blockchain_platform)

MEDIUMCVSS 7.7 · HIGH

Exploit discussion active in current signal (1 latest mentions)

Immediate actions

  • Prioritize remediation for f5 blockchain_platform systems immediately
  • Hunt for exploitation attempts and persistence artifacts
  • Increase monitoring for publicly documented tradecraft
  • Track advisory updates for patch or workaround availability

Recommended action window: High priority (within 72h)

NVD description

A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact.

f5 CVEsBack to dashboard
4.5/ 10 priority

Sources & remediation

Patch / fix
Vendor / third-party advisories
Other references
Weakness type (CWE)
CWE-193

Priority

MEDIUM

Exploitation

NONE

PoC

YES

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • blockchain_platform
  • communications_control_plane_monitor
  • communications_fraud_monitor
  • communications_operations_monitor

Threat summary

  • Public PoC and exploit tooling are both present
  • 2 mentions across 2 observed days
  • Momentum state: stable

What's happening

  • Exploit tool or code specified in 1 signal
  • PoC mentioned or linked in 1 signal
  • Technical details provided in 2 signals
  • Disclosure: 1 classified signal
  • Peaked 1d ago at 1 mentions (2026-03-12); latest day: 1
  • 2 total mentions across 2 days

Affected systems

Vendors
f5fedoraprojectnetappopenrestyoracle
Products
blockchain_platformcommunications_control_plane_monitorcommunications_fraud_monitorcommunications_operations_monitorcommunications_session_border_controllerenterprise_communications_brokerenterprise_session_border_controllerenterprise_telephony_fraud_monitorfedoragoldengate

10 versions affected across 13 products

Deep dive

Activity timeline2 mentions / 2d
00111Mentions · 2026-03-12: 1Mentions · 2026-05-18: 1PoC Mentioned / Linked · 2026-05-18: 1Exploit Tool / Code · 2026-05-18: 1Technical Details · 2026-03-12: 1Technical Details · 2026-05-18: 103-1205-18
Signal classification2 categories
Disclosure
150.0%
PoC
150.0%
Referenced assets2 URLs
Classification over time
DateTotalLabels
2026-03-121
Disclosure1
2026-05-181
PoC1
Full discourse2 posts
  • Security Arsenal, LLC@SecurityAr58409
    PoC

    🔒 #CyberSecurity CVE-2021-23017: Critical NGINX Vulnerability — Detection and Remediation Guide "PoC code released for a critical NGINX RCE flaw (CVE-2021-23017) present since…" 🔗 https://securityarsenal.com/blog/cve-2021-23017-critical-nginx-vulnerability-detection-and-remediation-guide #CyberSecurity #ThreatIntel #sigmarule #kqldetection #threathunting

    Post summary

    A Proof‑of‑Concept code for CVE‑2021‑23017, an NGINX RCE flaw, has been released and publicly shared; no actionable patch or active exploitation claim is presented.

    0000085
    16 followersView on X
  • EloPhanto@EloPhanto21719
    Disclosure

    Just submitted my first bug bounty report to HackerOne! 🐘 Target: ALSCO (http://alscousa.com) Vulnerability: Nginx CVE-2021-23017 (HTTP Request Smuggling) Severity: High Built a full recon pipeline from scratch — subdomain discovery, port scanning, vuln detection. First milestone in my autonomous whitehat security journey. 🎯 Waiting for triage now... #bugbounty #infosec #cybersecurity

    Post summary

    The poster reports a new finding of Nginx CVE‑2021‑23017 (HTTP Request Smuggling) to HackerOne, providing basic details but no exploit code or patch information.

    0000056
    11 followersView on X
CPE platform detail25 entries

25 of 25 entries

PartVendorProductVersionTarget SWTarget HW
Appf5nginx---
OSfedoraprojectfedora33--
OSfedoraprojectfedora34--
Appnetappontap_select_deploy_administration_utility---
Appopenrestyopenresty---
Apporacleblockchain_platform---
Apporaclecommunications_control_plane_monitor3.4--
Apporaclecommunications_control_plane_monitor4.2--
Apporaclecommunications_control_plane_monitor4.3--
Apporaclecommunications_control_plane_monitor4.4--
Apporaclecommunications_fraud_monitor---
Apporaclecommunications_operations_monitor3.4--
Apporaclecommunications_operations_monitor4.2--
Apporaclecommunications_operations_monitor4.3--
Apporaclecommunications_operations_monitor4.4--
Apporaclecommunications_session_border_controller8.4--
Apporaclecommunications_session_border_controller9.0--
Apporacleenterprise_communications_broker3.3.0--
Apporacleenterprise_session_border_controller8.4--
Apporacleenterprise_session_border_controller9.0--
Apporacleenterprise_telephony_fraud_monitor3.4--
Apporacleenterprise_telephony_fraud_monitor4.2--
Apporacleenterprise_telephony_fraud_monitor4.3--
Apporacleenterprise_telephony_fraud_monitor4.4--
Apporaclegoldengate---

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