Nx OsOperating system · Cisco

CVE-2019-1599

HIGH · 8.6 CVSS v3.1 Published 2019-03-07
Fix available
A fix is available. Upgrade to 3.2 / 4.0 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability in the network stack of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability is due to an issue with allocating and freeing memory buffers in the network stack. An attacker could exploit this vulnerability by sending crafted TCP streams to an affected device in a sustained way. A successful exploit could cause the network stack of an affected device to run out of available buffers, impairing operations of control plane and management plane protocols, resulting in a DoS condition. Note: This vulnerability can be triggered only by traffic that is destined to an affected device and cannot be exploited using traffic that transits an affected device. Nexus 1000V Switch for Microsoft Hyper-V is affected in versions prior to 5.2(1)SM3(2.1). Nexus 1000V Switch for VMware vSphere is affected in versions prior to 5.2(1)SV3(4.1a). Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(6) and 9.2(2). Nexus 3500 Platform Switches are affected in versions prior to 6.0(2)A8(11), 7.0(3)I7(6), and 9.2(2). Nexus 3600 Platform Switches are affected in versions prior to 7.0(3)F3(5) and 9.2(2). Nexus 5500, 5600, and 6000 Series Switches are affected in versions prior to 7.1(5)N1(1b) and 7.3(5)N1(1). Nexus 7000 and 7700 Series Switches are affected in versions prior to 6.2(22. Nexus 9500 R-Series Line Cards and Fabric Modules are affected in versions prior to 7.0(3)F3(5) and 9.2(2). UCS 6200 and 6300 Series Fabric Interconnect are affected in versions prior to 3.2(3j) and 4.0(2a). UCS 6400 Series Fabric Interconnect are affected in versions prior to 4.0(2a).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-399

A legacy NVD category grouping weaknesses in how resources — memory, file handles, connections — are allocated, used, and released. It gathers leaks, exhaustion, and lifecycle bugs under one label rather than naming a single flaw. The fix depends on the specific resource issue, generally pairing acquisition with release and bounding what any request can consume.

General guidance for the resource management errors class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Nx OsOperating system
Affected:>= 9.2, < 9.2\(2\)>= 7.0\(3\), < 7.0\(3\)i7\(5\)>= 7.0\(3\), < 7.0\(3\)f3\(5\)>= 7.2, < 7.3\(5\)n1\(1\)>= 8.3, < 8.3\(2\)< 6.0\(2\)a8\(11\)< 6.2\(22\)>= 7.0\(3\)i5, < 7.0\(3\)i7\(6\)< 5.2\(1\)sm3\(2.1\)< 5.2\(1\)sv3\(4.1a\)>= 4.0, < 4.0\(2a\)< 3.2\(3j\)

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 3.2 / 4.0 / 5.2 or later
Fixed in 3.24.05.2
Vendor patch tools.cisco.com →
We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-1599 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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