Vulnerability Monitor

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CVE-2018-20749

LibVNC before 0.9.12 contains a heap out-of-bounds write vulnerability in libvncserver/rfbserver.c. The fix for CVE-2018-15127 was incomplete.

Security Impact Summary

This vulnerability carries a CRITICAL severity rating with a CVSS v3.1 score of 9.8, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 15 products from libvnc_project, from canonical, from debian and 12 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

First disclosed in 2019, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.

Published

2019-01-30T18:29:00.410

Last Modified

2024-11-21T04:02:05.370

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 9.8 (CRITICAL)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:P/I:P/A:P

Access Vector: NETWORK
Access Complexity: LOW
Authentication: NONE
Confidentiality Impact: PARTIAL
Integrity Impact: PARTIAL
Availability Impact: PARTIAL

Exploitability Score

10.0

Impact Score

6.4

Weaknesses

Type: Primary
CWE-787

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	libvnc_project	libvncserver	< 0.9.12	Yes
Operating System	canonical	ubuntu_linux	14.04	Yes
Operating System	canonical	ubuntu_linux	16.04	Yes
Operating System	canonical	ubuntu_linux	16.04	Yes
Operating System	canonical	ubuntu_linux	18.04	Yes
Operating System	canonical	ubuntu_linux	18.10	Yes
Operating System	debian	debian_linux	8.0	Yes
Operating System	debian	debian_linux	9.0	Yes
Operating System	siemens	simatic_itc1500_firmware	< 3.2.1.0	Yes
Hardware	siemens	simatic_itc1500	-	No
Operating System	siemens	simatic_itc1500_pro_firmware	< 3.2.1.0	Yes
Hardware	siemens	simatic_itc1500_pro	-	No
Operating System	siemens	simatic_itc1900_firmware	< 3.2.1.0	Yes
Hardware	siemens	simatic_itc1900	-	No
Operating System	siemens	simatic_itc1900_pro_firmware	< 3.2.1.0	Yes
Hardware	siemens	simatic_itc1900_pro	-	No
Operating System	siemens	simatic_itc2200_firmware	< 3.2.1.0	Yes
Hardware	siemens	simatic_itc2200	-	No
Operating System	siemens	simatic_itc2200_pro_firmware	< 3.2.1.0	Yes
Hardware	siemens	simatic_itc2200_pro	-	No

References

http://www.securityfocus.com/bid/106825 Broken Link ([email protected])
https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf Patch, Third Party Advisory ([email protected])
https://github.com/LibVNC/libvncserver/commit/15bb719c03cc70f14c36a843dcb16ed69b405707 Patch, Third Party Advisory ([email protected])
https://github.com/LibVNC/libvncserver/issues/273 Issue Tracking, Third Party Advisory ([email protected])
https://lists.debian.org/debian-lts-announce/2019/01/msg00029.html Third Party Advisory ([email protected])
https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html Mailing List, Third Party Advisory ([email protected])
https://usn.ubuntu.com/3877-1/ Third Party Advisory ([email protected])
https://usn.ubuntu.com/4547-1/ Third Party Advisory ([email protected])
https://usn.ubuntu.com/4587-1/ Third Party Advisory ([email protected])
https://www.openwall.com/lists/oss-security/2018/12/10/8 Exploit, Mailing List, Third Party Advisory ([email protected])
http://www.securityfocus.com/bid/106825 Broken Link (af854a3a-2127-422b-91ae-364da2661108)
https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/LibVNC/libvncserver/commit/15bb719c03cc70f14c36a843dcb16ed69b405707 Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/LibVNC/libvncserver/issues/273 Issue Tracking, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.debian.org/debian-lts-announce/2019/01/msg00029.html Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://usn.ubuntu.com/3877-1/ Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://usn.ubuntu.com/4547-1/ Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://usn.ubuntu.com/4587-1/ Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.openwall.com/lists/oss-security/2018/12/10/8 Exploit, Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For libvnc_project's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.