CVE-2017-18922
CVE-2017-18922 is a critical-severity vulnerability in Libvncserver Project Libvncserver with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- CVSS v2: 7.5
- EPSS exploit prediction: 2% (81st percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-787
- Affected product: Libvncserver Project Libvncserver
- Published:
- Last modified:
Description
It was discovered that websockets.c in LibVNCServer prior to 0.9.12 did not properly decode certain WebSocket frames. A malicious attacker could exploit this by sending specially crafted WebSocket frames to a server, causing a heap-based buffer overflow.
Frequently asked questions
- What is CVE-2017-18922?
- It was discovered that websockets.c in LibVNCServer prior to 0.9.12 did not properly decode certain WebSocket frames. A malicious attacker could exploit this by sending specially crafted WebSocket frames to a server, causing a heap-based buffer overflow.
- How severe is CVE-2017-18922?
- CVE-2017-18922 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2017-18922 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2017-18922?
- CVE-2017-18922 primarily affects Libvncserver Project Libvncserver. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2017-18922?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2017-18922 published?
- CVE-2017-18922 was published on 2020-06-30 and last updated on 2026-06-17.
References
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00020.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00028.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html
- http://www.openwall.com/lists/oss-security/2020/06/30/3
- https://bugzilla.redhat.com/show_bug.cgi?id=1852356
- https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf
- https://github.com/LibVNC/libvncserver/commit/aac95a9dcf4bbba87b76c72706c3221a842ca433
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4F6FUH4EFK4NAP6GT4TQRTBKWIRCZLIY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVP7TJVYJDXDFRHVQ3ENEN3H354QPXEZ/
- https://usn.ubuntu.com/4407-1/
- https://www.openwall.com/lists/oss-security/2020/06/30/2
Affected products (15)
- cpe:2.3:a:libvncserver_project:libvncserver:*:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
- cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
- cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
- cpe:2.3:o:siemens:simatic_itc1500_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:siemens:simatic_itc1500_pro_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:siemens:simatic_itc1900_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:siemens:simatic_itc1900_pro_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:siemens:simatic_itc2200_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:siemens:simatic_itc2200_pro_firmware:*:*:*:*:*:*:*:*
More vulnerabilities in Libvncserver Project Libvncserver
- CVE-2018-7225 — Critical (CVSS 9.8): An issue was discovered in LibVNCServer through 0.9.11. rfbProcessClientNormalMessage() in rfbserver.c does not…
- CVE-2016-9942 — Critical (CVSS 9.8): Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a…
- CVE-2016-9941 — Critical (CVSS 9.8): Heap-based buffer overflow in rfbproto.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a…
- CVE-2026-32853 — High (CVSS 8.1): LibVNCServer versions 0.9.15 and prior (fixed in commit 009008e) contain a heap out-of-bounds read vulnerability in…
- CVE-2026-32854 — High (CVSS 7.5): LibVNCServer versions 0.9.15 and prior (fixed in commit dc78dee) contain null pointer dereference vulnerabilities in…
- CVE-2020-29260 — High (CVSS 7.5): libvncclient v0.9.13 was discovered to contain a memory leak via the function rfbClientCleanup().
All CVEs affecting Libvncserver Project Libvncserver →
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