Host-memory disclosure via undersized virtio-net header buffer
Published Jan 2, 2024 · Updated Feb 25, 2026
Stack-based buffer overflow in QEMU virtio-net on affected Red Hat Enterprise Linux hosts allows guest OS users to disclose host process memory. In virtio_net_flush_tx, n->guest_hdr_len can exceed the mhdr buffer, so iov_to_buf overwrites adjacent stack data including out_sg. Exploitation requires VIRTIO_NET_F_HASH_REPORT, VIRTIO_F_VERSION_1, and VIRTIO_NET_F_MRG_RXBUF; corrupted out_sg entries can transmit host-process bytes.
Summary
What happened
Stack-based buffer overflow in QEMU virtio-net on affected Red Hat Enterprise Linux hosts allows guest OS users to disclose host process memory. In virtio_net_flush_tx, n->guest_hdr_len can exceed the mhdr buffer, so iov_to_buf overwrites adjacent stack data including out_sg. Exploitation requires VIRTIO_NET_F_HASH_REPORT, VIRTIO_F_VERSION_1, and VIRTIO_NET_F_MRG_RXBUF; corrupted out_sg entries can transmit host-process bytes.
The record
- CVE
- CVE-2023-6693
- Published
- Jan 2, 2024
- Updated
- Feb 25, 2026
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8
- Classifications
- CWE-121, T1005
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 2, 2024CVE publishedPublication date reported by the CVE source.
- Feb 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo