High
Security advisory
An issue was discovered in LibVNCServer before 0.9.13. There is an information leak (of uninitialized memory contents) in the libvncclient/rfbproto.c ConnectToRFBRepeater function.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2018-21247
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 09:49 UTC · Revision 1
Source evidence
An issue was discovered in LibVNCServer before 0.9.13. There is an information leak (of uninitialized memory contents) in the libvncclient/rfbproto.c ConnectToRFBRepeater function.
osv:CVE-2018-21247
Complete source record
{
"id": "30678289a68db61b594f819b947a178c206ec2d518fe1e3e3ca233c236ba84aa",
"url": "https://osv.dev/vulnerability/CVE-2018-21247",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2018-21247",
"summary": "An issue was discovered in LibVNCServer before 0.9.13. There is an information leak (of uninitialized memory contents) in the libvncclient/rfbproto.c ConnectToRFBRepeater function.",
"evidence": "osv:CVE-2018-21247",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2018-21247",
"aliases": [
"CVE-2018-21247"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/libvnc/libvncserver",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"last_affected": "0a70095271d845d16a3ed17354841b01f33963ad"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:libvnc_project:libvncserver:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"last_affected": "0.9.12"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"LibVNCServer-0.9.12",
"LibVNCServer-0.9.11",
"LibVNCServer-0.9.10",
"LibVNCServer-0.9.9",
"LibVNCServer-0.9.8",
"X11VNC_0_9_12",
"X11VNC_0_9_11",
"X11VNC_0_9_10",
"X11VNC_0_9_9",
"X11VNC_0_9_8",
"X11VNC_0_9_7",
"X11VNC_REL_0_9_6",
"X11VNC_REL_0_9_5",
"X11VNC_REL_0_9_4"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-21247.json"
}
}
],
"modified": "2026-10-20T10:48:03.763019216Z",
"provider": "osv",
"references": [
"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://github.com/LibVNC/libvncserver/issues/253",
"https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf",
"https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:siemens:simatic_itc1500_firmware:*:*:*:*:*:*:*:*"
],
"vendor_product": "siemens:simatic_itc1500_firmware",
"extracted_events": [
{
"range": [
{
"introduced": "3.0.0.0"
},
{
"fixed": "3.2.1.0"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:siemens:simatic_itc1500_pro_firmware:*:*:*:*:*:*:*:*"
],
"vendor_product": "siemens:simatic_itc1500_pro_firmware",
"extracted_events": [
{
"range": [
{
"introduced": "3.0.0.0"
},
{
"fixed": "3.2.1.0"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:siemens:simatic_itc1900_firmware:*:*:*:*:*:*:*:*"
],
"vendor_product": "siemens:simatic_itc1900_firmware",
"extracted_events": [
{
"range": [
{
"introduced": "3.0.0.0"
},
{
"fixed": "3.2.1.0"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:siemens:simatic_itc1900_pro_firmware:*:*:*:*:*:*:*:*"
],
"vendor_product": "siemens:simatic_itc1900_pro_firmware",
"extracted_events": [
{
"range": [
{
"introduced": "3.0.0.0"
},
{
"fixed": "3.2.1.0"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:siemens:simatic_itc2200_firmware:*:*:*:*:*:*:*:*"
],
"vendor_product": "siemens:simatic_itc2200_firmware",
"extracted_events": [
{
"range": [
{
"introduced": "3.0.0.0"
},
{
"fixed": "3.2.1.0"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:siemens:simatic_itc2200_pro_firmware:*:*:*:*:*:*:*:*"
],
"vendor_product": "siemens:simatic_itc2200_pro_firmware",
"extracted_events": [
{
"range": [
{
"introduced": "3.0.0.0"
},
{
"fixed": "3.2.1.0"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*",
"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:18.10:*:*:*:*:*:*:*"
],
"vendor_product": "canonical:ubuntu_linux",
"extracted_events": [
{
"range": [
{
"introduced": "14.04"
},
{
"last_affected": "14.04"
},
{
"introduced": "16.04"
},
{
"last_affected": "16.04"
},
{
"introduced": "16.04"
},
{
"last_affected": "16.04"
},
{
"introduced": "18.04"
},
{
"last_affected": "18.04"
},
{
"introduced": "18.10"
},
{
"last_affected": "18.10"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*",
"cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"range": [
{
"introduced": "8.0"
},
{
"last_affected": "8.0"
},
{
"introduced": "9.0"
},
{
"last_affected": "9.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*"
],
"vendor_product": "opensuse:leap",
"extracted_events": [
{
"range": [
{
"introduced": "15.2"
},
{
"last_affected": "15.2"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2018-21247",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 379993,
"published_at": "2020-06-17T16:15:11.367+00:00"
}