CyberSecBulletin
CVE-2022-22185NVD status: Modified

Junos OS: Improper Check for Unusual or Exceptional Conditions

CVE-2022-22185 is a high-severity improper check for unusual or exceptional conditions vulnerability in Junos OS from Juniper Networks, 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. The record lists versions 18.3R3-S6, 17.3*, 18.4R3-S10 as the first without the flaw, so updating Junos OS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.97% 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 Junos OS to 18.3R3-S6 or 17.3* or 18.4R3-S10 or 19.1R3-S7, whichever matches your release line, or a later version.
  2. Read the advisory on kb.juniper.net 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
Juniper NetworksJunos OSbefore 18.3R3-S6; 17.3R1 up to, but not including, 17.3*; 18.4 up to, but not including, 18.4R3-S10; 19.1 up to, but not including, 19.1R3-S7; 19.2 up to, but not including, 19.2R3-S4; 19.3 up to, but not including, 19.3R3-S4; 19.4 up to, but not including, 19.4R3-S6; 20.1 up to, but not including, 20.1R3-S2; and 5 more ranges18.3R3-S6, 17.3*, 18.4R3-S10, 19.1R3-S7, 19.2R3-S4, 19.3R3-S4
Juniper NetworksJunos18.3; 18.4; 19.1; 19.2; 19.3; 19.4; 20.1; 20.2; and 4 more rangesNot stated

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
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (juniper.net)
CVSS 3.17.5HighNVD
CVSS 2.05.0MediumNVD

Official description

A vulnerability in Juniper Networks Junos OS on SRX Series, allows a network-based unauthenticated attacker to cause a Denial of Service (DoS) by sending a specific fragmented packet to the device, resulting in a flowd process crash, which is responsible for packet forwarding. Continued receipt and processing of this specific packet will create a sustained DoS condition. This issue only affects SRX Series when 'preserve-incoming-fragment-size' feature is enabled. This issue affects Juniper Networks Junos OS on SRX Series: 18.3 versions prior to 18.3R3-S6; 18.4 versions prior to 18.4R3-S10; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R3-S4; 19.3 versions prior to 19.3R3-S4; 19.4 versions prior to 19.4R3-S6; 20.1 versions prior to 20.1R3-S2; 20.2 versions prior to 20.2R3-S3; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2-S1, 21.1R3; 21.2 versions prior to 21.2R2. This issue does not affect Juniper Networks Junos OS prior to 17.3R1.

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

The underlying weakness: Improper Check for Unusual or Exceptional Conditions

The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Choose languages with features such as exception handling that force the programmer to anticipate unusual conditions that may generate exceptions. Custom exceptions may need to be developed to handle unusual business-logic conditions. Be careful not to pass sensitive exceptions back to the user (CWE-209, CWE-248).
  • Check the results of all functions that return a value and verify that the value is expected.
  • If using exception handling, catch and throw specific exceptions instead of overly-general exceptions (CWE-396, CWE-397). Catch and handle exceptions as locally as possible so that exceptions do not propagate too far up the call stack (CWE-705). Avoid unchecked or uncaught exceptions where feasible (CWE-248).

More Improper Check for Unusual or Exceptional Conditions vulnerabilities (CWE-754)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Junos OS

All Junos OS vulnerabilities

Recent Improper Check for Unusual or Exceptional Conditions vulnerabilities

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