CyberSecBulletin
CVE-2023-28973NVD status: Modified

Junos OS Evolved: Improper Authentication

CVE-2023-28973 is a high-severity improper authentication vulnerability in Junos OS Evolved from Juniper Networks, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 20.4R3-S5-EVO, 21.2R3-EVO, 21.3R2-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 0.15% 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 Evolved to 20.4R3-S5-EVO or 21.2R3-EVO or 21.3R2-EVO or 21.4R1-S2-EVO, 21.4R2-EVO, whichever matches your release line, or a later version.
  2. Read the advisory on supportportal.juniper.net for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Juniper NetworksJunos OS Evolvedbefore 20.4R3-S5-EVO; 21.2 up to, but not including, 21.2R3-EVO; 21.3 up to, but not including, 21.3R2-EVO; 21.4 up to, but not including, 21.4R1-S2-EVO, 21.4R2-EVO20.4R3-S5-EVO, 21.2R3-EVO, 21.3R2-EVO, 21.4R1-S2-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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H. Scored by CNA (juniper.net).

Official description

An Improper Authorization vulnerability in the 'sysmanctl' shell command of Juniper Networks Junos OS Evolved allows a local, authenticated attacker to execute administrative commands that could impact the integrity of the system or system availability. Administrative functions such as daemon restarting, routing engine (RE) switchover, and node shutdown can all be performed through exploitation of the 'sysmanctl' command. Access to the 'sysmanctl' command is only available from the Junos shell. Neither direct nor indirect access to 'sysmanctl' is available from the Junos CLI. This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R3-S5-EVO; 21.2 versions prior to 21.2R3-EVO; 21.3 versions prior to 21.3R2-EVO; 21.4 versions prior to 21.4R1-S2-EVO, 21.4R2-EVO.

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

The underlying weakness: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

How developers prevent this class of flaw

  • Use an authentication framework or library such as the OWASP ESAPI Authentication feature.

More Improper Authentication vulnerabilities (CWE-287)

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 Improper Authentication vulnerabilities

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