CVE-2021-3507: debian debian_linux
Vulnerability summary
CVE-2021-3507 is a medium (CVSS 6.1) vulnerability in debian debian_linux. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 42.1% of scored vulnerabilities. 1 public exploit is recorded.
Not severe (CVSS 6.1, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 10 · Related 8Timeline
- 06-05-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated6.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
- OSV · DebianEcosystem advisory · calculated6.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
- OSV · AlpineEcosystem advisory · calculated6.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
EPSS trend
Probability
0.49%
Chance of exploitation in the next 30 days
Percentile
42%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.49% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundExploit Reference (bugzilla.redhat.com)
Maturity: unknown
Weaknesses
CWE · root cause- CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.
- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian2 products
- qemu< 1:7.1+dfsg-1
- debian_linuxEOL10.0
Alpine1 product
- qemu< 6.1.0-r0
Qemu1 product
- qemu≤ 6.0.0
Redhat1 product
Ubuntu1 product
- qemu< 2.0.0+dfsg-2ubuntu1.47+esm6 | < 1:2.5+dfsg-5ubuntu10.51+esm4 | < 1:2.11+dfsg-1ubuntu7.40 | < 1:4.2-3ubuntu6.23 | < 1:6.2+dfsg-2ubuntu6.2
5 vendors · 6 products
References
10 links- bugzilla.redhat.com/show_bug.cgi?id=1951118X Refsource MISCExploitIssue TrackingThird Party Advisory
lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing ListX Refsource MLISTThird Party Advisory