CVE-2021-3507
Publication date 6 May 2021
Last updated 18 August 2025
Ubuntu priority
Description
A heap buffer overflow was found in the floppy disk emulator of QEMU up to 6.0.0 (including). It could occur in fdctrl_transfer_handler() in hw/block/fdc.c while processing DMA read data transfers from the floppy drive to the guest system. A privileged guest user could use this flaw to crash the QEMU process on the host resulting in DoS scenario, or potential information leakage from the host memory.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| qemu | 25.10 questing |
Fixed 1:6.2+dfsg-2ubuntu8
|
| 25.04 plucky |
Fixed 1:6.2+dfsg-2ubuntu8
|
|
| 24.04 LTS noble |
Fixed 1:6.2+dfsg-2ubuntu8
|
|
| 22.04 LTS jammy |
Fixed 1:6.2+dfsg-2ubuntu6.2
|
|
| 20.04 LTS focal |
Fixed 1:4.2-3ubuntu6.23
|
|
| 18.04 LTS bionic |
Fixed 1:2.11+dfsg-1ubuntu7.40
|
|
| 16.04 LTS xenial |
Vulnerable
|
|
| 14.04 LTS trusty |
Vulnerable
|
|
| qemu-kvm | 25.10 questing | Not in release |
| 25.04 plucky | Not in release | |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release |
Patch details
| Package | Patch details |
|---|---|
| qemu |
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
6.1 · Medium
|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | None |
| Availability impact | Low |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L |
References
Related Ubuntu Security Notices (USN)
- USN-5489-1
- QEMU vulnerabilities
- 21 June 2022