Buffer overflow in Cisco Nx-Os Software

CVE-2021-1590

A vulnerability in the implementation of the system login block-for command for Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a login process to unexpectedly restart, causing a denial of service (DoS) condition. This vulnerability is due to a logic error in the implementation of the system login block-for command when an attack is detected and acted upon. An attacker could exploit this vulnerability by performing a brute-force login attack on an affected device. A successful exploit could allow the attacker to cause a login process to reload, which could result in a delay during authentication to the affected device.

Vulnerability class: Buffer Overflow

EPSS: 0.014 (69.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

  • psirt@cisco.com (x_refsource_CISCO, vendor-advisory, Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-1590?
CVE-2021-1590 is a medium-severity vulnerability in Cisco Nx-Os Software, classified under Out-of-bounds Write. CVSS score: 5.3/10. Published 2021-08-25.
How severe is CVE-2021-1590?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2021-1590 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.