Cisco NX-OS Software Patch Signature Verification Bypass Vulnerability

published 2019-05-15 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-10366

cvss: 6.4; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits: 0; none known

A vulnerability in the Image Signature Verification feature of Cisco NX-OS Software could allow an authenticated, local attacker with administrator-level credentials to install a malicious software patch on an affected device. The vulnerability is due to improper verification of digital signatures for patch images. An attacker could exploit this vulnerability by crafting an unsigned software patch to bypass signature checks and loading it on an affected device. A successful exploit could allow the attacker to boot a malicious software patch image.

Patch / fix

fixed in 1

Cisco Cisco NX-OS Software 8.3(1)

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 23 mo ago (2024-11-20)

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	6.4	CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	6.7	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	4.6	AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected products

Cisco Cisco NX-OS Software

Classification

Weakness

CWE-347 Improper Verification of Cryptographic Signature

References

tools.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-nxos-psvb
vendor-advisory
securityfocus.com /bid/108375
vdb-entry, broken-link, third-party-advisory

Sources

CVE List CVE-2019-1809
NVD CVE-2019-1809

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Summary