Cisco FXOS and NX-OS Lightweight Directory Access Protocol Denial of Service Vulnerabilities
Multiple vulnerabilities in the implementation of the Lightweight Directory Access Protocol (LDAP) feature in Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerabilities are due to the improper parsing of LDAP packets by an affected device. An attacker could exploit these vulnerabilities by sending an LDAP packet crafted using Basic Encoding Rules (BER) to an affected device. The LDAP packet must have a source IP address of an LDAP server configured on the targeted device. A successful exploit could cause the affected device to reload, resulting in a DoS condition. Firepower 4100 Series Next-Generation Firewalls are affected in versions prior to 2.0.1.201, 2.2.2.54, and 2.3.1.75. Firepower 9300 Security Appliances are affected in versions prior to 2.0.1.201, 2.2.2.54 and 2.3.1.75. MDS 9000 Series Multilayer Switches are affected in versions prior to 8.2(1). Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(1). Nexus 3500 Platform Switches are affected in versions prior to 7.0(3)I7(2). Nexus 7000 and 7700 Series Switches are affected in versions prior to 8.2(1). Nexus 9000 Series Switches in Standalone NX-OS Mode are affected in versions prior to 7.0(3)I7(1). Cisco UCS 6200 and 6300 Fabric Interconnect devices are affected in versions prior to 3.2(2b).
- Published
- Mar 7, 2019
- Updated
- Jun 16, 2026
- EPSS
- 2.5% · 84th percentile
- CWE
- CWE-20
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.5
- CNA · cisco
- 8.6
- 1.1 point gap
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; 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 helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| cisco | firepower extensible operating system | cpe:2.3:o:cisco:firepower_extensible_operating_system |
| cisco | firepower 4100 | cpe:2.3:h:cisco:firepower_4100 |
| cisco | firepower 9300 | cpe:2.3:h:cisco:firepower_9300 |
| cisco | nx-os | cpe:2.3:o:cisco:nx-os |
| cisco | mds 9000 | cpe:2.3:h:cisco:mds_9000 |
| cisco | nexus 3000 | cpe:2.3:h:cisco:nexus_3000 |
| cisco | nexus 3500 | cpe:2.3:h:cisco:nexus_3500 |
| cisco | nexus 7000 | cpe:2.3:h:cisco:nexus_7000 |
| cisco | nexus 7700 | cpe:2.3:h:cisco:nexus_7700 |
| cisco | nexus 9000 | cpe:2.3:h:cisco:nexus_9000 |
| cisco | ucs 6200 | cpe:2.3:h:cisco:ucs_6200 |
| cisco | ucs 6300 | cpe:2.3:h:cisco:ucs_6300 |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cisco firepower extensible operating systemafter 2.2.2.54 · before 2.3.1.75
- cisco firepower extensible operating systemafter 2.0.1.201 · before 2.2.2.54
- cisco firepower extensible operating systembefore 2.0.1.201
- cisco nx-osbefore 7.0\(3\)i7\(2\)
- cisco nx-osafter 7.3\(2\)d1\(1\) · before 8.2\(1\)
- cisco nx-osbefore 3.2\(2b\)
- cisco nx-osafter 6.2\(20\) · before 7.3\(2\)d1\(1\)
- cisco nx-osbefore 6.2\(20\)
- cisco nx-osbefore 8.2\(1\)
- cisco nx-osbefore 7.0\(3\)i7\(1\)
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.
Cisco Cisco UCS 6200 and 6300 Fabric Interconnect
- unspecified and later · before 3.2(2b)affected
Cisco Firepower 4100 Series Next-Generation Firewalls
- unspecified and later · before 2.0.1.201affected
- unspecified and later · before 2.2.2.54affected
- unspecified and later · before 2.3.1.75affected
Cisco Firepower 9300 Security Appliance
- unspecified and later · before 2.0.1.201affected
- unspecified and later · before 2.2.2.54affected
- unspecified and later · before 2.3.1.75affected
Cisco MDS 9000 Series Multilayer Switches
- unspecified and later · before 8.2(1)affected
Cisco Nexus 3000 Series Switches
- unspecified and later · before 7.0(3)I7(1)affected
Cisco Nexus 3500 Platform Switches
- unspecified and later · before 7.0(3)I7(2)affected
Cisco Nexus 7000 and 7700 Series Switches
- unspecified and later · before 8.2(1)affected
Cisco Nexus 9000 Series Switches in Standalone NX-OS Mode
- unspecified and later · before 7.0(3)I7(1)affected
Same product
cisco: all recordsOther highest-scoring records for the same primary product.
- CVE-2015-6435An unspecified CGI script in Cisco FX-OS before 1.1.2 on Firepower 9000 devices and Cisco Unified Computing System (UCS) Manager before 2.2(42Plan
- CVE-2020-3172Cisco FXOS and NX-OS Software Cisco Discovery Protocol Arbitrary Code Execution and Denial of Service Vulnerability36Monitor
- CVE-2017-12277A vulnerability in the Smart Licensing Manager service of the Cisco Firepower 4100 Series Next-Generation Firewall (NGFW) and Firepower 930036Monitor
- CVE-2020-3456Cisco FXOS Software Firepower Chassis Manager Cross-Site Request Forgery Vulnerability35Monitor
- CVE-2017-3883A vulnerability in the authentication, authorization, and accounting (AAA) implementation of Cisco Firepower Extensible Operating System (FX35Monitor
- CVE-2020-3517Cisco FXOS and NX-OS Software Cisco Fabric Services Denial of Service Vulnerability34Monitor
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-19-018 · Mar 7, 2019(Cisco Güvenlik Güncellemeleri Yayınladı)
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
- high · 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
- High
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- www.securityfocus.com/bid/107394
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190306-nxosldap
Vendor advisories and official records. Exploit/PoC links are deliberately left out.