Qemu: vnc: infinite loop in inflate_buffer() leads to denial of service
Priority LOW 33CWE-835Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-835.
Summary
A flaw was found in the QEMU built-in VNC server while processing ClientCutText messages. A wrong exit condition may lead to an infinite loop when inflating an attacker controlled zlib buffer in the `inflate_buffer` function. This could allow a remote authenticated client who is able to send a clipboard to the VNC server to trigger a denial of service.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01891 79th percentileScored 2026-11-07
Fix Fixed Red Hat: 2 advisories
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 8 | — | 8100020240314161907.e155f54d | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | 8100020240314161907.e155f54d | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 17:8.2.0-11.el9_4 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 8 Advanced Virtualization | — | — | Not affected | CNA |
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 8100020240314161907.e155f54d Patch available CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 8100020240314161907.e155f54d Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 17:8.2.0-11.el9_4 Patch available CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 8 Advanced Virtualization VendorRed Hat Affected — Fixed in — Not affected CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:* | up to 8.0.3 | Vulnerable | QEMU |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Red Hat |
| cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:* | 38 | Vulnerable | Fedoraproject |
- cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:* Versions up to 8.0.3 Vulnerable ·QEMU
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
- cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:* Versions 38 Vulnerable ·Fedoraproject
Remediation
Red Hat 2 advisories
- RHSA-2024:2962 Released 2024-05-22 · Red Hat rating Moderatevirt:rhel and virt-devel:rhel security and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) SLOF-20210217-2.module+el8.10.0+20141+6faa2812.noarch::virt:rhel, SLOF-20210217-2.module+el8.10.0+20141+6faa2812.src::virt:rhel, hivex-1.3.18-23.module+el8.9.0+18724+20190c23.aarch64::virt:rhel +47
- Red Hat Enterprise Linux CRB (v. 8) SLOF-20210217-2.module+el8.10.0+20141+6faa2812.src::virt-devel:rhel, hivex-1.3.18-23.module+el8.9.0+18724+20190c23.i686::virt-devel:rhel, hivex-devel-1.3.18-23.module+el8.9.0+18724+20190c23.i686::virt-devel:rhel +47
- RHSA-2024:2135 Released 2024-04-30 · Red Hat rating Moderateqemu-kvm security update
- Red Hat Enterprise Linux AppStream (v. 9) qemu-guest-agent-17:8.2.0-11.el9_4, qemu-img-17:8.2.0-11.el9_4, qemu-kvm-17:8.2.0-11.el9_4 +17
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2024:2962 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2024:2135 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2024:2962 |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8 Advanced Virtualization
Timeline
- 2026-10-02 Threatist record created from CVE-2023-3255
- 2026-10-03 Alias added: GHSA-p5xv-5g6h-qw33
References
More Red Hat Enterprise Linux vulnerabilities
- TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2018-10530 Code injection in [UNKNOWN] RichFaces KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
- TI-2025-23530 Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf… KEVCVSS 3.1CRITICAL 9.3
- TI-2021-17490 mod_proxy SSRF KEVCVSS 3.1CRITICAL 9.0
Sources
- CVE-2023-3255 · CVE Program
- CVE-2023-3255 · NVD
- FIRST EPSS
- GHSA-p5xv-5g6h-qw33 · GitHub Advisory Database · CC BY 4.0
- CVE-2023-3255 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences