{"id":"CVE-2021-34856","aliases":["EUVD-2021-21503","GHSA-6pfq-pjhj-7hvv"],"status":"published","title":"This vulnerability allows local attackers to escalate privileges on affected installations of...","description":"This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.1.3 (49160). An attacker must first obtain the ability to execute high-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the virtio-gpu virtual device. The issue results from the lack of proper validation of user-supplied data, which can result in a memory corruption condition. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-13581.","severity":{"version":"3.0","score":8.2,"vector":"CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00267,"percentile":0.19013,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-119","CWE-787"],"published":"2021-10-25T17:10:41Z","modified":"2026-06-17T03:56:41Z","products":[{"vendor":"parallels","product":"desktop"},{"vendor":"parallels","product":"parallels_desktop"},{"vendor":"zen-browser","product":"desktop"}],"references":[{"url":"https://kb.parallels.com/125013","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-21-938/","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-34856"},{"url":"https://github.com/advisories/GHSA-6pfq-pjhj-7hvv"}],"sources":{"cve":[{"id":"CVE-2021-34856","description":"This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.1.3 (49160). An attacker must first obtain the ability to execute high-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the virtio-gpu virtual device. The issue results from the lack of proper validation of user-supplied data, which can result in a memory corruption condition. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-13581.","status":"published","published":"2021-10-25T17:10:41Z","modified":"2024-08-04T00:26:54.203Z","cvss":[{"version":"3.0","score":8.2,"vector":"CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-119"],"updated_at":"2026-11-02T14:33:11.244759Z"}],"euvd":[{"id":"EUVD-2021-21503","description":"This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.1.3 (49160). An attacker must first obtain the ability to execute high-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the virtio-gpu virtual device. The issue results from the lack of proper validation of user-supplied data, which can result in a memory corruption condition. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-13581.","status":"published","published":"2021-10-25T17:10:41Z","modified":"2024-08-04T00:26:54Z","cvss":[{"version":"3.0","score":8.2,"vector":"CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-03T03:24:31.977228Z"}],"ghsa":[{"id":"GHSA-6pfq-pjhj-7hvv","title":"This vulnerability allows local attackers to escalate privileges on affected installations of...","description":"This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.1.3 (49160). An attacker must first obtain the ability to execute high-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the virtio-gpu virtual device. The issue results from the lack of proper validation of user-supplied data, which can result in a memory corruption condition. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-13581.","status":"published","published":"2022-05-24T19:18:42Z","modified":"2023-01-29T05:02:40Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-119","CWE-787"],"updated_at":"2026-11-02T14:45:08.540426Z"}],"nvd":[{"id":"CVE-2021-34856","description":"This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.1.3 (49160). An attacker must first obtain the ability to execute high-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the virtio-gpu virtual device. The issue results from the lack of proper validation of user-supplied data, which can result in a memory corruption condition. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-13581.","status":"published","published":"2021-10-25T17:15:08.227Z","modified":"2026-06-17T03:56:41.367Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"3.0","score":8.2,"vector":"CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"2.0","score":4.6,"vector":"AV:L/AC:L/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-119","CWE-787"],"updated_at":"2026-11-02T14:07:00.137719Z"}]}}