{"id":"CVE-2024-21591","aliases":["EUVD-2024-19239","GHSA-j7xq-gvq8-pr7m"],"status":"published","title":"Junos OS: SRX Series and EX Series: Security Vulnerability in J-web allows a preAuth Remote Code Execution","description":"An Out-of-bounds Write vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS), or Remote Code Execution (RCE) and obtain root privileges on the device.\n\nThis issue is caused by use of an insecure function allowing an attacker to overwrite arbitrary memory.\n\nThis issue affects Juniper Networks Junos OS SRX Series and EX Series:\n\n\n\n  *  Junos OS versions earlier than 20.4R3-S9;\n  *  Junos OS 21.2 versions earlier than 21.2R3-S7;\n  *  Junos OS 21.3 versions earlier than 21.3R3-S5;\n  *  Junos OS 21.4 versions earlier than 21.4R3-S5;\n  *  Junos OS 22.1 versions earlier than 22.1R3-S4;\n  *  Junos OS 22.2 versions earlier than 22.2R3-S3;\n  *  Junos OS 22.3 versions earlier than 22.3R3-S2;\n  *  Junos OS 22.4 versions earlier than 22.4R2-S2, 22.4R3.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.17668,"percentile":0.97177,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-787"],"published":"2024-01-12T00:52:04Z","modified":"2026-06-17T07:09:46Z","products":[{"vendor":"juniper","product":"junos"},{"vendor":"juniper networks","product":"junos os"}],"references":[{"url":"https://supportportal.juniper.net/JSA75729","tags":["vendor-advisory","x_transferred","Vendor Advisory"]},{"url":"https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","tags":["technical-description","x_transferred","Third Party Advisory"]},{"url":"https://curesec.com/blog/article/CVE-2024-21591_Juniper_Remote_Code_Exec.html","tags":["third-party-advisory","x_transferred","Exploit","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-21591"},{"url":"https://github.com/advisories/GHSA-j7xq-gvq8-pr7m"}],"sources":{"cve":[{"id":"CVE-2024-21591","title":"Junos OS: SRX Series and EX Series: Security Vulnerability in J-web allows a preAuth Remote Code Execution","description":"\nAn Out-of-bounds Write vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS), or Remote Code Execution (RCE) and obtain root privileges on the device.\n\nThis issue is caused by use of an insecure function allowing an attacker to overwrite arbitrary memory.\n\nThis issue affects Juniper Networks Junos OS SRX Series and EX Series:\n\n\n\n  *  Junos OS versions earlier than 20.4R3-S9;\n  *  Junos OS 21.2 versions earlier than 21.2R3-S7;\n  *  Junos OS 21.3 versions earlier than 21.3R3-S5;\n  *  Junos OS 21.4 versions earlier than 21.4R3-S5;\n  *  Junos OS 22.1 versions earlier than 22.1R3-S4;\n  *  Junos OS 22.2 versions earlier than 22.2R3-S3;\n  *  Junos OS 22.3 versions earlier than 22.3R3-S2;\n  *  Junos OS 22.4 versions earlier than 22.4R2-S2, 22.4R3.\n\n\n\n\n\n\n","status":"published","published":"2024-01-12T00:52:04.028Z","modified":"2024-10-25T20:23:00.384Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"cna"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:34:04.681315Z"}],"euvd":[{"id":"EUVD-2024-19239","description":"\nAn Out-of-bounds Write vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS), or Remote Code Execution (RCE) and obtain root privileges on the device.\n\nThis issue is caused by use of an insecure function allowing an attacker to overwrite arbitrary memory.\n\nThis issue affects Juniper Networks Junos OS SRX Series and EX Series:\n\n\n\n  *  Junos OS versions earlier than 20.4R3-S9;\n  *  Junos OS 21.2 versions earlier than 21.2R3-S7;\n  *  Junos OS 21.3 versions earlier than 21.3R3-S5;\n  *  Junos OS 21.4 versions earlier than 21.4R3-S5;\n  *  Junos OS 22.1 versions earlier than 22.1R3-S4;\n  *  Junos OS 22.2 versions earlier than 22.2R3-S3;\n  *  Junos OS 22.3 versions earlier than 22.3R3-S2;\n  *  Junos OS 22.4 versions earlier than 22.4R2-S2, 22.4R3.\n\n\n\n\n\n\n","status":"published","published":"2024-01-12T00:52:04Z","modified":"2024-10-25T20:23:00Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-03T00:05:17.135828Z"}],"ghsa":[{"id":"GHSA-j7xq-gvq8-pr7m","title":"\nAn Out-of-bounds Write vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX...","description":"\nAn Out-of-bounds Write vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS), or Remote Code Execution (RCE) and obtain root privileges on the device.\n\nThis issue is caused by use of an insecure function allowing an attacker to overwrite arbitrary memory.\n\nThis issue affects Juniper Networks Junos OS SRX Series and EX Series:\n\n\n\n  *  Junos OS versions earlier than 20.4R3-S9;\n  *  Junos OS 21.2 versions earlier than 21.2R3-S7;\n  *  Junos OS 21.3 versions earlier than 21.3R3-S5;\n  *  Junos OS 21.4 versions earlier than 21.4R3-S5;\n  *  Junos OS 22.1 versions earlier than 22.1R3-S4;\n  *  Junos OS 22.2 versions earlier than 22.2R3-S3;\n  *  Junos OS 22.3 versions earlier than 22.3R3-S2;\n  *  Junos OS 22.4 versions earlier than 22.4R2-S2, 22.4R3.\n\n\n\n\n\n\n","status":"published","published":"2024-01-12T03:30:48Z","modified":"2024-02-10T00:31:59Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:55:35.197353Z"}],"nvd":[{"id":"CVE-2024-21591","description":"\nAn Out-of-bounds Write vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS), or Remote Code Execution (RCE) and obtain root privileges on the device.\n\nThis issue is caused by use of an insecure function allowing an attacker to overwrite arbitrary memory.\n\nThis issue affects Juniper Networks Junos OS SRX Series and EX Series:\n\n\n\n  *  Junos OS versions earlier than 20.4R3-S9;\n  *  Junos OS 21.2 versions earlier than 21.2R3-S7;\n  *  Junos OS 21.3 versions earlier than 21.3R3-S5;\n  *  Junos OS 21.4 versions earlier than 21.4R3-S5;\n  *  Junos OS 22.1 versions earlier than 22.1R3-S4;\n  *  Junos OS 22.2 versions earlier than 22.2R3-S3;\n  *  Junos OS 22.3 versions earlier than 22.3R3-S2;\n  *  Junos OS 22.4 versions earlier than 22.4R2-S2, 22.4R3.\n\n\n\n\n\n\n","status":"published","published":"2024-01-12T01:15:46.697Z","modified":"2026-06-17T07:09:46.79Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:09:30.070039Z"}]}}