CyberSecBulletin
CVE-2022-20730NVD status: Modified

Cisco Firepower Threat Defense Software: Improper Handling of Unexpected Data Type

Published Updated By the CyberSecBulletin desk

CVE-2022-20730 is a high-severity improper handling of unexpected data type vulnerability in Cisco Firepower Threat Defense Software from Cisco, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.99% chance of exploitation within 30 days, higher than 63% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Secure Firewall Threat Defense to 6.4.0.15 or 6.6.5.2 or 7.0.2, whichever matches your release line, or a later version.
  2. Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco Firepower Threat Defense SoftwareNot specified in the recordNot stated
CiscoSecure Firewall Threat Defensebefore 6.4.0.15; 6.5.0 up to, but not including, 6.6.5.2; 6.7.0 up to, but not including, 7.0.26.4.0.15, 6.6.5.2, 7.0.2

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
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 3.14.0MediumCNA (cisco.com)
CVSS 3.17.5HighNVD
CVSS 2.05.0MediumNVD

Official description

A vulnerability in the Security Intelligence feed feature of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the Security Intelligence DNS feed. This vulnerability is due to incorrect feed update processing. An attacker could exploit this vulnerability by sending traffic through an affected device that should be blocked by the affected device. A successful exploit could allow the attacker to bypass device controls and successfully send traffic to devices that are expected to be protected by the affected device.

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

The underlying weakness: Improper Handling of Unexpected Data Type

The product does not handle or incorrectly handles when a particular element is not the expected type, e.g. it expects a digit (0-9) but is provided with a letter (A-Z).

How developers prevent this class of flaw

  • Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

More Improper Handling of Unexpected Data Type vulnerabilities (CWE-241)

Timeline

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

References

Other vulnerabilities in Cisco Firepower Threat Defense Software

All Cisco Firepower Threat Defense Software vulnerabilities

Recent Improper Handling of Unexpected Data Type vulnerabilities

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