Cisco NX-OS Software 802.1X Extensible Authentication Protocol over LAN Denial of Service Vulnerability
Cisco · Nexus 1000V Switch for VMware vSphere
A vulnerability in the 802.1X implementation for Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incomplete input validation of Extensible Authentication Protocol over LAN (EAPOL) frames. An attacker could exploit this vulnerability by sending a crafted EAPOL frame to an interface on the targeted device. A successful exploit could allow the attacker to cause the Layer 2 (L2) forwarding process to restart multiple times, leading to a system-level restart of the device and a DoS condition. Note: This vulnerability affects only NX-OS devices configured with 802.1X functionality. Cisco Nexus 1000V Switch for VMware vSphere devices are affected in versions prior to 5.2(1)SV3(1.4b). Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(4). Nexus 3500 Platform Switches are affected in versions prior to 7.0(3)I7(4). Nexus 2000, 5500, 5600, and 6000 Series Switches are affected in versions prior to 7.3(5)N1(1) and 7.1(5)N1(1b). Nexus 7000 and 7700 Series Switches are affected in versions prior to 8.2(3). Nexus 9000 Series Fabric Switches in ACI Mode are affected in versions prior to 13.2(1l). Nexus 9000 Series Switches in Standalone NX-OS Mode are affected in versions prior to 7.0(3)I7(4).
- Exploited
- Not confirmed
- Reports
- 0
- Tactics
- 2/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
Disclosed on 6 Mar 2019. No public exploit code or confirmed exploitation is recorded.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
2 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order 2Initial AccessTA0001
ImpactTA0040
Detection
0 rules for this CVE · 152 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2019-1594 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Exploit Public-Facing ApplicationT1190149 general rules
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- CVE-2010-5278 Exploitation Attemptcriticaltest
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- CVE-2020-10148 SolarWinds Orion API Auth Bypasscriticaltest
- CVE-2020-5902 F5 BIG-IP Exploitation Attemptcriticaltest
Application or System ExploitationT1499.0043 general rules
- Audit CVE Eventcriticaltest
- Apache Segmentation Faulthightest
- Nginx Core Dumphightest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 3 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Spam “Broken Seal” DocuSign-themed Delivery w/Fileless Process Hollowing (Zeppelin/Bloat-A) by msudosos22 Mar 2026
- Spam “Broken Seal” DocuSign-themed Delivery w/Fileless Process Hollowing (Zeppelin/Bloat-A) by msudosos22 Mar 2026
- “Broken Seal” DocuSign-themed Delivery with Fileless Process Hollowing (Zeppelin/Bloat-A)13 Feb 2026