JunosOperating system · Juniper

CVE-2023-44177

MEDIUM · 5.5 CVSS v3.1 Published 2023-10-13
Fix available
A fix is available. Upgrade to 20.4 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A Stack-based Buffer Overflow vulnerability in the CLI command of Juniper Networks Junos and Junos EVO allows a low privileged attacker to execute a specific CLI commands leading to Denial of Service. Repeated actions by the attacker will create a sustained Denial of Service (DoS) condition. This issue affects Juniper Networks: Junos OS: * All versions prior to 19.1R3-S10; * 19.2 versions prior to 19.2R3-S7; * 19.3 versions prior to 19.3R3-S8; * 19.4 versions prior to 19.4R3-S12; * 20.2 versions prior to 20.2R3-S8; * 20.4 versions prior to 20.4R3-S8; * 21.2 versions prior to 21.2R3-S6; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S1; * 22.3 versions prior to 22.3R3; * 22.4 versions prior to 22.4R2. Junos OS Evolved: * All versions prior to 20.4R3-S8-EVO; * 21.2 versions prior to 21.2R3-S6-EVO; * 21.3 versions prior to 21.3R3-S5-EVO; * 21.4 versions prior to 21.4R3-S4-EVO; * 22.1 versions prior to 22.1R3-S3-EVO; * 22.2 versions prior to 22.2R3-S1-EVO; * 22.3 versions prior to 22.3R3-EVO; * 22.4 versions prior to 22.4R2-EVO.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A stack-based buffer overflow vulnerability exists in the CLI command parsing component of Juniper Networks Junos and Junos EVO operating systems. A low-privileged attacker with CLI access can trigger the overflow by executing a specific malformed CLI command, causing a denial of service. Repeated exploitation leads to sustained DoS conditions.

MitigationApply the vendor-supplied software updates that address this vulnerability. Refer to the Juniper Networks security advisory for the specific patched versions corresponding to each affected Junos OS and Junos EVO release train.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
JunosOperating system
Affected:< 20.4= 20.4= 21.2= 21.3= 21.4= 22.1= 22.2= 22.3= 22.4
Junos Os EvolvedOperating system
Affected:< 20.4= 20.4= 21.2= 21.3= 21.4= 22.1= 22.2= 22.3= 22.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Junos product variant
    Execute 'show version' or 'show version detail' at the CLI prompt to determine if the device is running Junos or Junos EVO
    Affected if The device runs Juniper Junos or Junos EVO
  2. Determine the installed Junos version
    From the 'show version' output, record the exact version string displayed (for example, 21.4R3 or 22.2R1)
    Affected if The installed version matches any of these: < 20.4, = 20.4, = 21.2, = 21.3, = 21.4, = 22.1, = 22.2, = 22.3, = 22.4
  3. Confirm CLI access exists on the device
    Verify that CLI (commit, operational, or configuration mode) is accessible and functional on the device
    Affected if CLI access is available to a low-privileged user (the vulnerability is exploitable through CLI command parsing)
  4. Review the specific CLI command that triggers the overflow
    Refer to the Juniper Networks security advisory for the exact malformed CLI command syntax required to trigger this vulnerability
    Affected if A user can execute the specific malformed CLI command described in the advisory

You are affected if your device runs Junos or Junos EVO AND your installed version matches any of the listed affected versions AND CLI access is available to an attacker who can execute the malformed command.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 20.4 or later
Fixed in 20.4
Interim mitigation

Apply the vendor-supplied software updates that address this vulnerability. Refer to the Juniper Networks security advisory for the specific patched versions corresponding to each affected Junos OS and Junos EVO release train.

Recommended fix High confidence

Junos OS: 22.4R2 or later; Junos OS Evolved: 22.4R2-EVO or later (or the corresponding R3-Sx release for your branch)

  1. 1. Identify the current Junos OS or Junos OS Evolved version running on the device using 'show version'
  2. 2. Based on the installed version, plan upgrade to the minimum fixed release for your branch: For 19.1.x upgrade to 19.1R3-S10 or later; For 19.2.x upgrade to 19.2R3-S7 or later; For 19.3.x upgrade to 19.3R3-S8 or later; For 19.4.x upgrade to 19.4R3-S12 or later; For 20.2.x upgrade to 20.2R3-S8 or later; For 20.4.x upgrade to 20.4R3-S8 or later; For 21.2.x upgrade to 21.2R3-S6 or later; For 21.3.x
  3. 3. For Junos OS Evolved: Upgrade to 20.4R3-S8-EVO, 21.2R3-S6-EVO, 21.3R3-S5-EVO, 21.4R3-S4-EVO, 22.1R3-S3-EVO, 22.2R3-S1-EVO, 22.3R3-EVO, or 22.4R2-EVO respectively
  4. 4. Download the appropriate Junos upgrade package from the Juniper Networks support portal
  5. 5. Upload the upgrade package to the device via FTP/SCP
  6. 6. Execute the upgrade command: 'request system software add <package_name>' for Junos OS or follow the standard upgrade procedure for Junos OS Evolved
  7. 7. Reboot the device after upgrade completes using 'request system reboot'
  8. 8. Verify the new version is installed and the device is functioning normally using 'show version'
Caveat Standard Junos upgrade risks apply - ensure valid configuration backup and plan maintenance window as upgrade may cause brief service interruption

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Junos Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
Get the upgrade done

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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-44177 in production — separate from our analysis above.

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What this is

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What belongs here
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