CVE-2023-3354: Improper i/o watch removal in tls handshake can lead to remote unauthenticated denial of service
Vulnerability summary
CVE-2023-3354 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in fedoraproject fedora. EPSS estimates a 1.61% chance of exploitation in the next 30 days, higher than 75.9% of scored vulnerabilities.
Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 2% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 15 · Related 10Timeline
- 11-07-2023PublishedVulnerability first disclosed.
- 13-02-2025Last modifiedVulnerability information updated.
Description
A flaw was found in the QEMU built-in VNC server. When a client connects to the VNC server, QEMU checks whether the current number of connections crosses a certain threshold and if so, cleans up the previous connection. If the previous connection happens to be in the handshake phase and fails, QEMU cleans up the connection again, resulting in a NULL pointer dereference issue. This could allow a remote unauthenticated client to cause a denial of service.
CVSS metrics
5 scores · 5 sources · 1 version- OSV · Red hatEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
1.61%
Chance of exploitation in the next 30 days
Percentile
76%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.61% 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
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Redhat48 products
- enterprise_linuxEOL7.0 | 8.0 | 9.0
- openstack_platform13.0
- qemu-guest-agent< 17:7.2.0-14.el9_2.5 | < 17:6.2.0-11.el9_0.8
- qemu-guest-agent-debuginfo< 17:7.2.0-14.el9_2.5 | < 17:6.2.0-11.el9_0.8
- qemu-img< 17:7.2.0-14.el9_2.5 | < 17:6.2.0-11.el9_0.8
Debian1 product
- qemu< 1:7.2+dfsg-7+deb12u2 | < 1:8.0.4+dfsg-1
Fedoraproject1 product
- fedoraEOL38
Qemu1 product
- qemu< 8.1.0 | 8.1.0:rc0 | 8.1.0:rc1
Ubuntu1 product
- qemu< 1:2.11+dfsg-1ubuntu7.42+esm5 | < 1:4.2-3ubuntu6.28 | < 1:6.2+dfsg-2ubuntu6.16
5 vendors · 52 products
References
18 links- lists.fedoraproject.org/archives/…Mailing List
