An issue was discovered in LibVNCServer through 0.9.11.
An issue was discovered in LibVNCServer through 0.9.11. rfbProcessClientNormalMessage() in rfbserver.c does not sanitize msg.cct.length, leading to access to uninitialized and potentially sensitive data or possibly unspecified other impact (e.g., an integer overflow) via specially crafted VNC packets.
- Published
- Feb 19, 2018
- Updated
- Jun 16, 2026
- EPSS
- 6.1% · 93th percentile
- CWE
- CWE-190
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Report tools
Action score
41
Plan
Add it to your regular patch cycle.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 2 / 30 · 6.1%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| libvncserver project | libvncserver | cpe:2.3:a:libvncserver_project:libvncserver |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| canonical | ubuntu linux | cpe:2.3:o:canonical:ubuntu_linux |
| redhat | enterprise linux desktop | cpe:2.3:o:redhat:enterprise_linux_desktop |
| redhat | enterprise linux server | cpe:2.3:o:redhat:enterprise_linux_server |
| redhat | enterprise linux server aus | cpe:2.3:o:redhat:enterprise_linux_server_aus |
| redhat | enterprise linux server eus | cpe:2.3:o:redhat:enterprise_linux_server_eus |
| redhat | enterprise linux server tus | cpe:2.3:o:redhat:enterprise_linux_server_tus |
| redhat | enterprise linux workstation | cpe:2.3:o:redhat:enterprise_linux_workstation |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- canonical ubuntu linux14.04
- canonical ubuntu linux16.04
- canonical ubuntu linux17.10
- debian debian linux7.0
- debian debian linux8.0
- debian debian linux9.0
- libvncserver project libvncserverup to 0.9.11 inclusive
- redhat enterprise linux desktop7.0
- redhat enterprise linux server7.0
- redhat enterprise linux server aus7.6
- redhat enterprise linux server eus7.5
- redhat enterprise linux server eus7.6
- redhat enterprise linux server tus7.6
- redhat enterprise linux workstation7.0
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.10 | libvncserver | before 0.9.11-r2 | 0.9.11-r2 |
| Alpine:v3.5 | libvncserver | before 0.9.11-r1 | 0.9.11-r1 |
| Debian:12 | libvncserver | before 0.9.11+dfsg-1.1 | 0.9.11+dfsg-1.1 |
| Debian:12 | tightvnc | before 1:1.3.9-9.1 | 1:1.3.9-9.1 |
| Debian:12 | vino | before 3.22.0-6 | 3.22.0-6 |
| Debian:7 | libvncserver | before 0.9.9+dfsg-1+deb7u3 | 0.9.9+dfsg-1+deb7u3 |
| Debian:8 | italc | before 1:2.0.2+dfsg1-2+deb8u1 | 1:2.0.2+dfsg1-2+deb8u1 |
| Debian:8 | libvncserver | before 0.9.9+dfsg2-6.1+deb8u3 | 0.9.9+dfsg2-6.1+deb8u3 |
| Debian:8 | tightvnc | before 1.3.9-6.5+deb8u1 | 1.3.9-6.5+deb8u1 |
| Debian:8 | vino | before 3.14.0-2+deb8u1 | 3.14.0-2+deb8u1 |
| Debian:9 | libvncserver | before 0.9.11+dfsg-1+deb9u1 | 0.9.11+dfsg-1+deb9u1 |
| Red Hat:enterprise_linux:7::client | libvncserver | before 0:0.9.9-12.el7_5 | 0:0.9.9-12.el7_5 |
| Red Hat:enterprise_linux:7::client | libvncserver-debuginfo | before 0:0.9.9-12.el7_5 | 0:0.9.9-12.el7_5 |
| Red Hat:enterprise_linux:7::client | libvncserver-devel | before 0:0.9.9-12.el7_5 | 0:0.9.9-12.el7_5 |
| SUSE:Linux Enterprise Server for Raspberry Pi 12 SP2 | LibVNCServer | before 0.9.9-17.5.1 | 0.9.9-17.5.1 |
| SUSE:Linux Enterprise Software Development Kit 11 SP4 | LibVNCServer | before 0.9.1-160.3.1 | 0.9.1-160.3.1 |
Same product
libvncserver project: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-18922It was discovered that websockets.c in LibVNCServer prior to 0.9.12 did not properly decode certain WebSocket frames.40Plan
- CVE-2016-9942Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (appl40Plan
- CVE-2016-9941Heap-based buffer overflow in rfbproto.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (a40Plan
- CVE-2020-14400An issue was discovered in LibVNCServer before 0.9.13.31Monitor
- CVE-2020-14399An issue was discovered in LibVNCServer before 0.9.13.31Monitor
- CVE-2010-5304A NULL pointer dereference flaw was found in the way LibVNCServer before 0.9.9 handled certain ClientCutText message.31Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| alpine:libvncserver | 0.9.11-r2 · Alpine:v3.10 | Package registry (OSV) |
| debian:italc | 1:2.0.2+dfsg1-2+deb8u1 · Debian:8 | Package registry (OSV) |
| debian:libvncserver | 0.9.11+dfsg-1.1 · Debian:12 | Package registry (OSV) |
| debian:tightvnc | 1:1.3.9-9.1 · Debian:12 | Package registry (OSV) |
| debian:vino | 3.22.0-6 · Debian:12 | Package registry (OSV) |
| red hat:libvncserver | 0:0.9.9-12.el7_5 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:libvncserver-debuginfo | 0:0.9.9-12.el7_5 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:libvncserver-devel | 0:0.9.9-12.el7_5 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| suse:LibVNCServer | 0.9.9-17.5.1 · SUSE:Linux Enterprise Server for Raspberry Pi 12 SP2 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-190 · Integer Overflow or WraparoundCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- usn.ubuntu.com/4573-1/
- usn.ubuntu.com/4587-1/
- usn.ubuntu.com/3618-1/
- usn.ubuntu.com/4547-1/
- www.securityfocus.com/bid/103107
- access.redhat.com/errata/RHSA-2018:1055
- github.com/LibVNC/libvncserver/issues/218
- lists.debian.org/debian-lts-announce/2018/03/msg00035.html
- lists.debian.org/debian-lts-announce/2019/10/msg00042.html
- lists.debian.org/debian-lts-announce/2019/11/msg00032.html
- lists.debian.org/debian-lts-announce/2019/12/msg00028.html
- security.gentoo.org/glsa/201908-05
- www.debian.org/security/2018/dsa-4221
Vendor advisories and official records. Exploit/PoC links are deliberately left out.