CyberSecBulletin
CVE-2022-22223NVD status: Modified

On QFX10000 Series devices using Juniper Networks Junos OS when configured as transit IP/MPLS…

CVE-2022-22223 is a high-severity improper input validation 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 15.1R7-S11, 18.4R2-S10, 18.4R3-S10, 19.1R3-S8 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 0.91% chance of exploitation within 30 days, higher than 61% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Junos OS to 15.1R7-S11 or 18.4R2-S10, 18.4R3-S10 or 19.1R3-S8 or 19.2R3-S4, whichever matches your release line, or a later version.
  2. Update Junos to 15.1 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 15.1R7-S11; 18.4 up to, but not including, 18.4R2-S10, 18.4R3-S10; 19.1 up to, but not including, 19.1R3-S8; 19.2 up to, but not including, 19.2R3-S4; 19.3 up to, but not including, 19.3R3-S5; 19.4 up to, but not including, 19.4R2-S6, 19.4R3-S7; 20.1 up to, but not including, 20.1R3-S3; 20.2 up to, but not including, 20.2R3-S3; and 5 more ranges15.1R7-S11, 18.4R2-S10, 18.4R3-S10, 19.1R3-S8, 19.2R3-S4, 19.3R3-S5, 19.4R2-S6, 19.4R3-S7
Juniper NetworksJunosbefore 15.1; 15.1; 18.4; 19.1; 19.2; 19.3; 19.4; 20.1; and 6 more ranges15.1

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 3.16.5MediumCNA (juniper.net)
CVSS 3.17.5HighNVD

Official description

On QFX10000 Series devices using Juniper Networks Junos OS when configured as transit IP/MPLS penultimate hop popping (PHP) nodes with link aggregation group (LAG) interfaces, an Improper Validation of Specified Index, Position, or Offset in Input weakness allows an attacker sending certain IP packets to cause multiple interfaces in the LAG to detach causing a Denial of Service (DoS) condition. Continued receipt and processing of these packets will sustain the Denial of Service. This issue affects IPv4 and IPv6 packets. Packets of either type can cause and sustain the DoS event. These packets can be destined to the device or be transit packets. On devices such as the QFX10008 with line cards, line cards can be restarted to restore service. On devices such as the QFX10002 you can restart the PFE service, or reboot device to restore service. This issue affects: Juniper Networks Junos OS on QFX10000 Series: All versions prior to 15.1R7-S11; 18.4 versions prior to 18.4R2-S10, 18.4R3-S10; 19.1 versions prior to 19.1R3-S8; 19.2 versions prior to 19.2R3-S4; 19.3 versions prior to 19.3R3-S5; 19.4 versions prior to 19.4R2-S6, 19.4R3-S7; 20.1 versions prior to 20.1R3-S3; 20.2 versions prior to 20.2R3-S3; 20.3 versions prior to 20.3R3-S2; 20.4 versions prior to 20.4R3-S4; 21.1 versions prior to 21.1R3; 21.2 versions prior to 21.2R3-S3; 21.3 versions prior to 21.3R3-S1. An indicator of compromise may be seen by issuing the command: request pfe execute target fpc0 command "show jspec pechip[3] registers ps l2_node 10" timeout 0 | refresh 1 | no-more and reviewing for backpressured output; for example: GOT: 0x220702a8 pe.ps.l2_node[10].pkt_cnt 00000076 GOT: 0x220702b4 pe.ps.l2_node[10].backpressured 00000002 <<<< STICKS HERE and requesting detail on the pepic wanio: request pfe execute target fpc0 command "show pepic 0 wanio-info" timeout 0 | no-more | match xe-0/0/0:2 GOT: 3 xe-0/0/0:2 10 6 3 0 1 10 189 10 0x6321b088 <<< LOOK HERE as well as looking for tail drops looking at the interface queue, for example: show interfaces queue xe-0/0/0:2 resulting in: Transmitted: Total-dropped packets: 1094137 0 pps << LOOK HERE

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

The underlying weakness: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How developers prevent this class of flaw

  • Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.

More Improper Input Validation vulnerabilities (CWE-20)

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

Advisories

Other vulnerabilities in Junos OS

All Junos OS vulnerabilities

Recent Improper Input Validation vulnerabilities

Spotted an error? Tell us.