CyberSecBulletin
CVE-2022-22153NVD status: Modified

Junos OS: Inefficient Algorithmic Complexity

CVE-2022-22153 is a high-severity inefficient algorithmic complexity 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 18.2R3, 18.3R3, 18.4R2-S9, 18.4R3 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 0.96% chance of exploitation within 30 days, higher than 62% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Junos OS to 18.2R3 or 18.3R3 or 18.4R2-S9, 18.4R3 or 19.1R2, whichever matches your release line, or a later version.
  2. Update Junos to 18.2 or a later version.
  3. Read the advisory on kb.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 OSbefore 18.2R3; 18.3 up to, but not including, 18.3R3; 18.4 up to, but not including, 18.4R2-S9, 18.4R3; 19.1 up to, but not including, 19.1R2; 19.2 up to, but not including, 19.2R1-S1, 19.2R218.2R3, 18.3R3, 18.4R2-S9, 18.4R3, 19.1R2, 19.2R1-S1, 19.2R2
Juniper NetworksJunosbefore 18.2; 18.2; 18.3; 18.4; 19.1; 19.218.2

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
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

An Insufficient Algorithmic Complexity combined with an Allocation of Resources Without Limits or Throttling vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series and MX Series with SPC3 allows an unauthenticated network attacker to cause latency in transit packet processing and even packet loss. If transit traffic includes a significant percentage (> 5%) of fragmented packets which need to be reassembled, high latency or packet drops might be observed. This issue affects Juniper Networks Junos OS on SRX Series, MX Series with SPC3: All versions prior to 18.2R3; 18.3 versions prior to 18.3R3; 18.4 versions prior to 18.4R2-S9, 18.4R3; 19.1 versions prior to 19.1R2; 19.2 versions prior to 19.2R1-S1, 19.2R2.

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

The underlying weakness: Inefficient Algorithmic Complexity

An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.

More Inefficient Algorithmic Complexity vulnerabilities (CWE-407)

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

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