A Denial of Service vulnerability in the Telnet remote login functionality of Cisco NX-OS Software running on Cisco Nexus 9000 Series Switch
A Denial of Service vulnerability in the Telnet remote login functionality of Cisco NX-OS Software running on Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to cause a Telnet process used for login to terminate unexpectedly and the login attempt to fail. There is no impact to user traffic flowing through the device. Affected Products: This vulnerability affects Cisco Nexus 9000 Series Switches that are running Cisco NX-OS Software and are configured to allow remote Telnet connections to the device. More Information: CSCux46778. Known Affected Releases: 7.0(3)I3(0.170). Known Fixed Releases: 7.0(3)I3(1) 7.0(3)I3(0.257) 7.0(3)I3(0.255) 7.0(3)I2(2e) 7.0(3)F1(1.22) 7.0(3)F1(1).
- Published
- Mar 17, 2017
- Updated
- Jun 16, 2026
- EPSS
- 2.9% · 87th percentile
- CWE
- CWE-119
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.9%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| cisco | nx-os | cpe:2.3:o:cisco:nx-os |
| cisco | nexus 92160yc switch | cpe:2.3:h:cisco:nexus_92160yc_switch |
| cisco | nexus 92300yc switch | cpe:2.3:h:cisco:nexus_92300yc_switch |
| cisco | nexus 92304qc switch | cpe:2.3:h:cisco:nexus_92304qc_switch |
| cisco | nexus 9236c switch | cpe:2.3:h:cisco:nexus_9236c_switch |
| cisco | nexus 9272q switch | cpe:2.3:h:cisco:nexus_9272q_switch |
| cisco | nexus 93108tc-ex switch | cpe:2.3:h:cisco:nexus_93108tc-ex_switch |
| cisco | nexus 93120tx switch | cpe:2.3:h:cisco:nexus_93120tx_switch |
| cisco | nexus 93128tx switch | cpe:2.3:h:cisco:nexus_93128tx_switch |
| cisco | nexus 93180lc-ex switch | cpe:2.3:h:cisco:nexus_93180lc-ex_switch |
| cisco | nexus 93180yc-ex switch | cpe:2.3:h:cisco:nexus_93180yc-ex_switch |
| cisco | nexus 9332pq switch | cpe:2.3:h:cisco:nexus_9332pq_switch |
and 8 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cisco nx-os7.0(3)i3(0.170)
Versions reported by the vendor
Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.
n/a Cisco Nexus 9000 Series Switches
- Cisco Nexus 9000 Series Switchesaffected
Same product
cisco: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-20399Cisco NX-OS Software CLI Command Injection VulnerabilityKEV57Plan
- CVE-2018-0301A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to craft a packet to the manag44Plan
- CVE-2016-1453Buffer overflow in the Overlay Transport Virtualization (OTV) GRE feature in Cisco NX-OS 5.0 through 7.3 on Nexus 7000 and 7700 devices allo41Plan
- CVE-2018-0310A vulnerability in the Cisco Fabric Services component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remot40Plan
- CVE-2022-20650Cisco NX-OS Software NX-API Command Injection Vulnerability39Monitor
- CVE-2016-1341Cisco NX-OS 7.0(1)N1(1), 7.0(1)N1(3), and 7.0(4)N1(1) on Nexus 2000 Fabric Extender devices has a blank root password, which allows local us39Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- Low
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Buffer ManipulationCAPEC-123likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- www.securityfocus.com/bid/96927
- www.securitytracker.com/id/1038047
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-nss
Vendor advisories and official records. Exploit/PoC links are deliberately left out.