CVE-2021-3682

A flaw was found in the USB redirector device emulation of QEMU in versions prior to 6.1.0-rc2. It occurs when dropping packets during a bulk transfer from a SPICE client due to the packet queue being full. A malicious SPICE client could use this flaw to make QEMU call free() with faked heap chunk metadata, resulting in a crash of QEMU or potential code execution with the privileges of the QEMU process on the host.

• CWE-763
• CWE-763

• https://bugzilla.redhat.com/show_bug.cgi?id=1989651Issue Tracking, Patch, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/09/msg00000.htmlThird Party Advisory
• https://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing List, Third Party Advisory
• https://security.gentoo.org/glsa/202208-27Third Party Advisory
• https://security.netapp.com/advisory/ntap-20210902-0006/Third Party Advisory
• https://www.debian.org/security/2021/dsa-4980Third Party Advisory
• https://bugzilla.redhat.com/show_bug.cgi?id=1989651Issue Tracking, Patch, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2021/09/msg00000.htmlThird Party Advisory
• https://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing List, Third Party Advisory
• https://security.gentoo.org/glsa/202208-27Third Party Advisory
• https://security.netapp.com/advisory/ntap-20210902-0006/Third Party Advisory
• https://www.debian.org/security/2021/dsa-4980Third Party Advisory

Published

Aug 5, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-36814Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…
• CVE-2021-36815Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…
• CVE-2021-36816Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…
• CVE-2021-36817Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…
• CVE-2021-36818Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…
• CVE-2021-36819Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…
• CVE-2021-36820Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…
• CVE-2021-36821Improper Neutralization of Input During Web Page Generation …6.1
• CVE-2021-36823Improper Neutralization of Input During Web Page Generation …8.2
• CVE-2021-36826Authenticated (subscriber or higher user role if allowed to …5.4
• CVE-2021-36827Auth. (admin+) Stored Cross-Site Scripting (XSS) vulnerabili…4.8
• CVE-2021-36828Authenticated (admin+) Stored Cross-Site Scripting (XSS) in …4.8