CyberSecBulletin
CVE-2024-21614NVD status: Modified

Junos OS: Improper Check for Unusual or Exceptional Conditions

CVE-2024-21614 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 22.2R2-S2, 22.2R3, 22.3R2, 22.3R3 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 0.69% chance of exploitation within 30 days, higher than 54% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Junos OS to 22.2R2-S2, 22.2R3 or 22.3R2, 22.3R3, whichever matches your release line, or a later version.
  2. Update Junos OS Evolved to 22.2R2-S2-EVO, 22.2R3-EVO or 22.3R2-EVO, 22.3R3-EVO, whichever matches your release line, or a later version.
  3. Read the advisory on supportportal.juniper.net for workarounds and exact fixed builds.
  4. 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 OS22.2 up to, but not including, 22.2R2-S2, 22.2R3; 22.3 up to, but not including, 22.3R2, 22.3R322.2R2-S2, 22.2R3, 22.3R2, 22.3R3
Juniper NetworksJunos OS Evolved22.2 up to, but not including, 22.2R2-S2-EVO, 22.2R3-EVO; 22.3 up to, but not including, 22.3R2-EVO, 22.3R3-EVO22.2R2-S2-EVO, 22.2R3-EVO, 22.3R2-EVO, 22.3R3-EVO
Juniper NetworksJunos22.2; 22.3Not 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

Official description

An Improper Check for Unusual or Exceptional Conditions vulnerability in Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based, unauthenticated attacker to cause rpd to crash, leading to Denial of Service (DoS). On all Junos OS and Junos OS Evolved platforms, when NETCONF and gRPC are enabled, and a specific query is executed via Dynamic Rendering (DREND), rpd will crash and restart. Continuous execution of this specific query will cause a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS * 22.2 versions earlier than 22.2R2-S2, 22.2R3; * 22.3 versions earlier than 22.3R2, 22.3R3. Juniper Networks Junos OS Evolved * 22.2 versions earlier than 22.2R2-S2-EVO, 22.2R3-EVO; * 22.3 versions earlier than 22.3R2-EVO, 22.3R3-EVO. This issue does not affect Juniper Networks: Junos OS versions earlier than 22.2R1; Junos OS Evolved versions earlier than 22.2R1-EVO.

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. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. 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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