Junos OS: An local attacker with shell access can execute arbitrary code

Primary CVSS: v4.0 6.7 MEDIUM from [email protected]

CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.017350000 probability, percentile 0.775040000 (date 2026-10-26)

CISA KEV: Listed on 2025-03-13; due 2025-04-03; ransomware use Unknown

Problem Types: CWE-653 | CWE-653 CWE-653 Improper Isolation or Compartmentalization

Discovery Credit

CNA: Juniper SIRT would like to acknowledge and thank Matteo Memelli from Amazon for responsibly reporting this issue. Note: Amazon found the issue during internal security research and not due to exploitation. (en)

Solutions

CNA: The following software releases have been updated to resolve this specific issue: 21.2R3-S9, 21.4R3-S10, 22.2R3-S6, 22.4R3-S6, 23.2R2-S3, 23.4R2-S4, 24.2R1-S2, 24.2R2, 24.4R1, and all subsequent releases.   Please note that this issue is not fixed for all platforms in the releases specified in the solution section. For the following products the fix is only available in these releases: SRX300 Series   21.2R3-S9, 23.4R2-S5*, 24.4R1 SRX550HM    22.2R3-S7* EX4300 Series     21.4R3-S11* (except EX4300-48MP which has fixes available as indicated in the solution) EX4600               21.4R3-S11* (except EX4650 which has fixes available as indicated in the solution) ACX1000, ACX1100, ACX2100, ACX2200, ACX4000, ACX500              21.2R3-S9 MX104               21.2R3-S9 * Future Release

Workarounds

CNA: It is strongly recommended to mitigate the risk of exploitation by restricting shell access to trusted users only.

Exploits

CNA: At least one instance of malicious exploitation has been reported to the Juniper SIRT. Customers are encouraged to upgrade to a fixed release as soon as it's available and in the meantime take steps to mitigate this vulnerability.