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CVE-2023-22400NVD status: Modified

Junos OS Evolved: Uncontrolled Resource Consumption

CVE-2023-22400 is a high-severity uncontrolled resource consumption vulnerability in Junos OS Evolved 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 20.4R3-S3-EVO, 21.1-EVO*, 21.2R3-S4-EVO as the first without the flaw, so updating Junos OS Evolved to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.66% chance of exploitation within 30 days, higher than 52% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Junos OS Evolved to 20.4R3-S3-EVO or 21.1-EVO* or 21.2R3-S4-EVO or 21.3-EVO*, 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 OS Evolvedbefore 20.4R3-S3-EVO; 21.1R1-EVO up to, but not including, 21.1-EVO*; 21.2-EVO up to, but not including, 21.2R3-S4-EVO; 21.3R1-EVO up to, but not including, 21.3-EVO*; 21.4-EVO up to, but not including, 21.4R2-EVO20.4R3-S3-EVO, 21.1-EVO*, 21.2R3-S4-EVO, 21.3-EVO*, 21.4R2-EVO

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 CNA (juniper.net).

Official description

An Uncontrolled Resource Consumption vulnerability in the PFE management daemon (evo-pfemand) of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause an FPC crash leading to a Denial of Service (DoS). When a specific SNMP GET operation or a specific CLI command is executed this will cause a GUID resource leak, eventually leading to exhaustion and result in an FPC crash and reboot. GUID exhaustion will trigger a syslog message like one of the following for example: evo-pfemand[<pid>]: get_next_guid: Ran out of Guid Space ... evo-aftmand-zx[<pid>]: get_next_guid: Ran out of Guid Space ... This leak can be monitored by running the following command and taking note of the value in the rightmost column labeled Guids: user@host> show platform application-info allocations app evo-pfemand | match "IFDId|IFLId|Context" Node Application Context Name Live Allocs Fails Guids re0 evo-pfemand net::juniper::interfaces::IFDId 0 3448 0 3448 re0 evo-pfemand net::juniper::interfaces::IFLId 0 561 0 561 user@host> show platform application-info allocations app evo-pfemand | match "IFDId|IFLId|Context" Node Application Context Name Live Allocs Fails Guids re0 evo-pfemand net::juniper::interfaces::IFDId 0 3784 0 3784 re0 evo-pfemand net::juniper::interfaces::IFLId 0 647 0 647 This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R3-S3-EVO; 21.1-EVO version 21.1R1-EVO and later versions; 21.2-EVO versions prior to 21.2R3-S4-EVO; 21.3-EVO version 21.3R1-EVO and later versions; 21.4-EVO versions prior to 21.4R2-EVO.

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

The underlying weakness: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How developers prevent this class of flaw

  • Ensure that protocols have specific limits of scale placed on them.
  • Ensure that all failures in resource allocation place the system into a safe posture.

More Uncontrolled Resource Consumption vulnerabilities (CWE-400)

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 Junos OS Evolved

All Junos OS Evolved vulnerabilities

Recent Uncontrolled Resource Consumption vulnerabilities

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