cbcvebase.
CVE-2021-1361
published 2021-02-24

CVE-2021-1361: A vulnerability in the implementation of an internal file management service for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in…

PriorityP263critical9.1CVSS 3.1
AVNACLPRNUINSUCNIHAH
EPSS
1.57%
72.7th percentile
A vulnerability in the implementation of an internal file management service for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode that are running Cisco NX-OS Software could allow an unauthenticated, remote attacker to create, delete, or overwrite arbitrary files with root privileges on the device. This vulnerability exists because TCP port 9075 is incorrectly configured to listen and respond to external connection requests. An attacker could exploit this vulnerability by sending crafted TCP packets to an IP address that is configured on a local interface on TCP port 9075. A successful exploit could allow the attacker to create, delete, or overwrite arbitrary files, including sensitive files that are related to the device configuration. For example, the attacker could add a user account without the device administrator knowing.

Affected

4 ranges
VendorProductVersion rangeFixed in
ciscocisco_nx-os_software
cisconx-os
cisconx-os
cisconx-os

Detection & IOCsextracted from sources · hover to see the quote

portTCP/9075
  • Monitor for inbound TCP connections to port 9075 on any locally configured IP address of Cisco Nexus 3000/9000 devices; any external connection to this port is anomalous and indicative of exploitation attempts.
  • Alert on unexpected user account creation on NX-OS devices, which may indicate successful exploitation resulting in unauthorized account addition.
  • Detect unauthorized creation, deletion, or overwriting of files — especially device configuration files — on Cisco Nexus 3000/9000 switches running standalone NX-OS mode.
  • ·The vulnerability only affects Cisco Nexus 3000 and 9000 Series Switches running in standalone NX-OS mode; other deployment modes are not affected.
  • ·The service listens on all locally configured IP interfaces, meaning any reachable interface IP (not just management) can be targeted on TCP/9075.
  • ·A workaround exists in addition to the software fix; operators should consult the Cisco advisory for workaround details.

CVSS provenance

nvdv3.19.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
nvdv2.09.4CRITICALAV:N/AC:L/Au:N/C:N/I:C/A:C
vendor_cisco9.8CRITICAL
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.