CyberSecBulletin
CVE-2022-20964NVD status: Modified

Cisco Identity Services Engine Software: Improper Neutralization of Special Elements used in an OS Command

CVE-2022-20964 is a high-severity improper neutralization of special elements used in an OS command vulnerability in Cisco Identity Services Engine 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 Identity Services Engine Software versions: 2.6.0; 2.6.0 p1; 2.6.0 p2, 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 30.6% chance of exploitation within 30 days, which is in the top 1.73% of all scored CVEs.

Patch this week

EPSS places it among the vulnerabilities most likely to be exploited soon.

What to do

  1. Update Identity Services Engine to 2.6.0 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 Identity Services Engine Software2.6.0; 2.6.0 p1; 2.6.0 p2; 2.6.0 p3; 2.6.0 p5; 2.6.0 p6; 2.6.0 p7; 2.6.0 p8; and 24 more rangesNot stated
CiscoIdentity Services Enginebefore 2.6.0; 2.6.0; 2.7.0; 3.0.0; 3.1; 3.22.6.0

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 3.16.3MediumCNA (cisco.com)
CVSS 3.18.8HighNVD

Official description

A vulnerability in the web-based management interface of Cisco Identity Services Engine could allow an authenticated, remote attacker to inject arbitrary commands on the underlying operating system. This vulnerability is due to improper validation of user input within requests as part of the web-based management interface. An attacker could exploit this vulnerability by manipulating requests to the web-based management interface to contain operating system commands. A successful exploit could allow the attacker to execute arbitrary operating system commands on the underlying operating system with the privileges of the web services user. Cisco has not yet released software updates that address this vulnerability.

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

The underlying weakness: Improper Neutralization of Special Elements used in an OS Command

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.

How developers prevent this class of flaw

  • If at all possible, use library calls rather than external processes to recreate the desired functionality.
  • For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco Identity Services Engine Software

All Cisco Identity Services Engine Software vulnerabilities

Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities

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