Buffer overflow in Qemu
CVE-2023-6693
A stack based buffer overflow was found in the virtio-net device of QEMU. This issue occurs when flushing TX in the virtio_net_flush_tx function if guest features VIRTIO_NET_F_HASH_REPORT, VIRTIO_F_VERSION_1 and VIRTIO_NET_F_MRG_RXBUF are enabled. This could allow a malicious user to overwrite local variables allocated on the stack. Specifically, the `out_sg` variable could be used to read a part of process memory and send it to the wire, causing an information leak.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (23.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 23.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Qemu
- Fedoraproject Fedora — versions 39
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8 — versions 8100020240314161907.e155f54d
- Red Hat Enterprise Linux 8 Advanced Virtualization
- Red Hat Enterprise Linux 9 — versions 17:9.0.0-10.el9_5.3
- Red Hat Enterprise Linux — versions 8.0, 9.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- access.redhat.com/errata/RHSA-2024:2962 (vendor-advisory)
- access.redhat.com/errata/RHSA-2025:4492 (vendor-advisory)
- access.redhat.com/security/cve/CVE-2023-6693 (Third Party Advisory, vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Patch, Issue Tracking)
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2023-6693?
- CVE-2023-6693 is a medium-severity vulnerability in Qemu, classified under Stack-based Buffer Overflow. CVSS score: 4.9/10. Published 2024-01-02.
- How severe is CVE-2023-6693?
- Medium severity. CVSS v3 base score is 4.9 out of 10.
- Is CVE-2023-6693 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.