CyberSecBulletin
CVE-2023-20235NVD status: Modified

Cisco IOS XE Software: Improper Privilege Management

CVE-2023-20235 is a high-severity improper privilege management vulnerability in Cisco IOS XE Software from Cisco, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Cisco IOS XE Software versions: 17.3.1; 17.3.2; 17.3.3, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.86% chance of exploitation within 30 days, higher than 59% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update iOS Xe to 17.3.1 or a later version.
  2. Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco IOS XE Software17.3.1; 17.3.2; 17.3.3; 17.3.1a; 17.3.1w; 17.3.2a; 17.3.1x; 17.3.1z; and 32 more rangesNot stated
CiscoiOS Xebefore 17.3.117.3.1

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.16.5MediumCNA (cisco.com)
CVSS 3.18.8HighNVD

Official description

A vulnerability in the on-device application development workflow feature for the Cisco IOx application hosting infrastructure in Cisco IOS XE Software could allow an authenticated, remote attacker to access the underlying operating system as the root user. This vulnerability exists because Docker containers with the privileged runtime option are not blocked when they are in application development mode. An attacker could exploit this vulnerability by using the Docker CLI to access an affected device. The application development workflow is meant to be used only on development systems and not in production systems.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Privilege Management

The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

How developers prevent this class of flaw

  • Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.

More Improper Privilege Management vulnerabilities (CWE-269)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco IOS XE Software

All Cisco IOS XE Software vulnerabilities

Recent Improper Privilege Management vulnerabilities

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