CyberSecBulletin
CVE-2022-22156NVD status: Modified

Junos OS: Improper Certificate Validation

CVE-2022-22156 is a high-severity improper certificate validation vulnerability in Junos OS from Juniper Networks, with a CVSS 3.1 base score of 7.4 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 18.4R2-S9, 18.4R3-S9, 19.1R2-S3, 19.1R3-S7, 19.2R1-S7, 19.2R3-S3 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 0.57% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Junos OS to 18.4R2-S9, 18.4R3-S9 or 19.1R2-S3, 19.1R3-S7 or 19.2R1-S7, 19.2R3-S3 or 19.3R3-S4, 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 18.4R2-S9, 18.4R3-S9; 19.1 up to, but not including, 19.1R2-S3, 19.1R3-S7; 19.2 up to, but not including, 19.2R1-S7, 19.2R3-S3; 19.3 up to, but not including, 19.3R3-S4; 19.4 up to, but not including, 19.4R3-S7; 20.1 up to, but not including, 20.1R2-S2, 20.1R3; 20.2 up to, but not including, 20.2R3; 20.3 up to, but not including, 20.3R2-S1, 20.3R3; and 2 more ranges18.4R2-S9, 18.4R3-S9, 19.1R2-S3, 19.1R3-S7, 19.2R1-S7, 19.2R3-S3, 19.3R3-S4, 19.4R3-S7, 20.1R2-S2, 20.1R3
Juniper NetworksJunos18.3 and earlier; 18.4; 19.1; 19.2; 19.3; 19.4; 20.1; 20.2; and 3 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
HighSuccess depends on conditions outside the attacker's control.
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
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 3.16.5MediumCNA (juniper.net)
CVSS 3.17.4HighNVD
CVSS 2.05.8MediumNVD

Official description

An Improper Certificate Validation weakness in the Juniper Networks Junos OS allows an attacker to perform Person-in-the-Middle (PitM) attacks when a system script is fetched from a remote source at a specified HTTPS URL, which may compromise the integrity and confidentiality of the device. The following command can be executed by an administrator via the CLI to refresh a script from a remote location, which is affected from this vulnerability: >request system scripts refresh-from (commit | event | extension-service | op | snmp) file filename url <https-url> This issue affects: Juniper Networks Junos OS All versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R2-S3, 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R3-S4; 19.4 versions prior to 19.4R3-S7; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R2-S1, 20.3R3; 20.4 versions prior to 20.4R2; 21.1 versions prior to 21.1R1-S1, 21.1R2.

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

The underlying weakness: Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate.

How developers prevent this class of flaw

  • Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
  • If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.

More Improper Certificate Validation vulnerabilities (CWE-295)

Timeline

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

References

Advisories

Other vulnerabilities in Junos OS

All Junos OS vulnerabilities

Recent Improper Certificate Validation vulnerabilities

Spotted an error? Tell us.