{"id":"CVE-2021-0210","aliases":["EUVD-2021-2829","GHSA-4gh5-fw3f-vm8m"],"status":"published","title":"Junos OS: Privilege escalation in J-Web due to arbitrary command and code execution via information disclosure from another users active session","description":"An Information Exposure vulnerability in J-Web of Juniper Networks Junos OS allows an unauthenticated attacker to elevate their privileges over the target system through opportunistic use of an authenticated users session. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S17; 17.3 versions prior to 17.3R3-S10; 17.4 versions prior to 17.4R2-S12, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.3 versions prior to 18.3R2-S4, 18.3R3-S4; 18.4 versions prior to 18.4R2-S5, 18.4R3-S5; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3; 19.2 versions prior to 19.2R1-S5, 19.2R3, 19.2R3-S1; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R1-S4, 20.1R2; 20.2 versions prior to 20.2R1-S1, 20.2R2.","severity":{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01114,"percentile":0.66302,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-200"],"published":"2021-01-15T17:35:56Z","modified":"2026-06-17T03:29:29Z","products":[{"vendor":"juniper","product":"junos"},{"vendor":"juniper networks","product":"junos os"}],"references":[{"url":"https://kb.juniper.net/JSA11100","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-0210"},{"url":"https://github.com/advisories/GHSA-4gh5-fw3f-vm8m"}],"sources":{"cve":[{"id":"CVE-2021-0210","title":"Junos OS: Privilege escalation in J-Web due to arbitrary command and code execution via information disclosure from another users active session","description":"An Information Exposure vulnerability in J-Web of Juniper Networks Junos OS allows an unauthenticated attacker to elevate their privileges over the target system through opportunistic use of an authenticated users session. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S17; 17.3 versions prior to 17.3R3-S10; 17.4 versions prior to 17.4R2-S12, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.3 versions prior to 18.3R2-S4, 18.3R3-S4; 18.4 versions prior to 18.4R2-S5, 18.4R3-S5; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3; 19.2 versions prior to 19.2R1-S5, 19.2R3, 19.2R3-S1; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R1-S4, 20.1R2; 20.2 versions prior to 20.2R1-S1, 20.2R2.","status":"published","published":"2021-01-15T17:35:56.895Z","modified":"2024-09-16T22:26:01.525Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:33:10.555814Z"}],"euvd":[{"id":"EUVD-2021-2829","description":"An Information Exposure vulnerability in J-Web of Juniper Networks Junos OS allows an unauthenticated attacker to elevate their privileges over the target system through opportunistic use of an authenticated users session. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S17; 17.3 versions prior to 17.3R3-S10; 17.4 versions prior to 17.4R2-S12, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.3 versions prior to 18.3R2-S4, 18.3R3-S4; 18.4 versions prior to 18.4R2-S5, 18.4R3-S5; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3; 19.2 versions prior to 19.2R1-S5, 19.2R3, 19.2R3-S1; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R1-S4, 20.1R2; 20.2 versions prior to 20.2R1-S1, 20.2R2.","status":"published","published":"2021-01-15T17:35:56Z","modified":"2024-09-16T22:26:01Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium"}],"updated_at":"2026-11-03T00:55:02.946444Z"}],"ghsa":[{"id":"GHSA-4gh5-fw3f-vm8m","title":"An Information Exposure vulnerability in J-Web of Juniper Networks Junos OS allows an...","description":"An Information Exposure vulnerability in J-Web of Juniper Networks Junos OS allows an unauthenticated attacker to elevate their privileges over the target system through opportunistic use of an authenticated users session. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S17; 17.3 versions prior to 17.3R3-S10; 17.4 versions prior to 17.4R2-S12, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.3 versions prior to 18.3R2-S4, 18.3R3-S4; 18.4 versions prior to 18.4R2-S5, 18.4R3-S5; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3; 19.2 versions prior to 19.2R1-S5, 19.2R3, 19.2R3-S1; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R1-S4, 20.1R2; 20.2 versions prior to 20.2R1-S1, 20.2R2.","status":"published","published":"2022-05-24T17:39:20Z","modified":"2023-01-29T05:05:24Z","cwes":["CWE-200"],"updated_at":"2026-11-02T14:45:46.865713Z"}],"nvd":[{"id":"CVE-2021-0210","description":"An Information Exposure vulnerability in J-Web of Juniper Networks Junos OS allows an unauthenticated attacker to elevate their privileges over the target system through opportunistic use of an authenticated users session. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S17; 17.3 versions prior to 17.3R3-S10; 17.4 versions prior to 17.4R2-S12, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.3 versions prior to 18.3R2-S4, 18.3R3-S4; 18.4 versions prior to 18.4R2-S5, 18.4R3-S5; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3; 19.2 versions prior to 19.2R1-S5, 19.2R3, 19.2R3-S1; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R1-S4, 20.1R2; 20.2 versions prior to 20.2R1-S1, 20.2R2.","status":"published","published":"2021-01-15T18:15:15.09Z","modified":"2026-06-17T03:29:29.723Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium","assessor":"secondary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:P/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:06:49.284888Z"}]}}