CyberSecBulletin
CVE-2022-20739NVD status: Modified

Cisco SD-WAN vManage: Improper Privilege Management

CVE-2022-20739 is a high-severity improper privilege management vulnerability in Cisco SD-WAN vManage from Cisco, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. There is no confirmed exploitation so far. EPSS estimates a 0.6% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Sd-wan Vmanage to 20.6.1 or a later version.
  2. Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco SD-WAN vManageNot specified in the recordNot stated
CiscoCatalyst Sd-wan Manager20.7Not stated
CiscoSd-wan Vmanagebefore 20.6.120.6.1

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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
RequiredA user must take an action such as opening a file or link.
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:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.3HighCNA (cisco.com)
CVSS 3.17.3HighNVD
CVSS 2.08.5HighNVD

Official description

A vulnerability in the CLI of Cisco SD-WAN vManage Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying operating system as the root user. The attacker must be authenticated on the affected system as a low-privileged user to exploit this vulnerability. This vulnerability exists because a file leveraged by a root user is executed when a low-privileged user runs specific commands on an affected system. An attacker could exploit this vulnerability by injecting arbitrary commands to a specific file as a lower-privileged user and then waiting until an admin user executes specific commands. The commands would then be executed on the device by the root user. A successful exploit could allow the attacker to escalate their privileges on the affected system from a low-privileged user to the root user.

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 SD-WAN vManage

All Cisco SD-WAN vManage vulnerabilities

Recent Improper Privilege Management vulnerabilities

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