Home/CVE/UltraVNC revision 1207 has multiple out-of-bounds access vulnerabilities connected with improper usage of SETPIXELS macr
CVE
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CVE-2019-8265

UltraVNC revision 1207 has multiple out-of-bounds access vulnerabilities connected with improper usage of SETPIXELS macr

UltraVNC revision 1207 has multiple out-of-bounds access vulnerabilities connected with improper usage of SETPIXELS macro in VNC client code, which can potentially result in code execution. This attack appears to be exploitable via network connectivity. These vulnerabilities have been fixed in revision 1208.

CRITICAL · CVSS 9.8 EPSS 0.03142
EPSS exploitation odds3.14% · top 13%
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules2 YARA rules0
Look this up elsewhere - one-click external pivots
NVDCVE.orgCISAExploit-DBGitHub PoCVulnCheck KEVGreyNoise
▸ How to read a CVE - triage first, then detect and patch
This page is every public fact about CVE-2019-8265, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.
Triage: should I act now? Four signals, and they are not interchangeable:
CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.
How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.
Then what - two workflows:
Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.
Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).
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Exploitation momentum

1237 days of EPSS
dormant
Flat and low - no real exploitation pressure. This reads the direction and speed of EPSS over time, which can move before EPSS itself peaks or before CISA lists it.
Window
▣

Severity & exploitation scoring

View on NVD →
CVSS base score
9.8
CRITICALCVSS v3.0 · [email protected]
EPSS exploitation probability
3.14%
Top 13%odds of exploitation in the next 30 days
CVSS metric silhouette
VectorComplexityPrivilegesInteractionScopeConfidentialityIntegrityAvailability
shape grows toward worst-case
SSVC triage
No SSVC vulnrichment for this CVE. CISA's Vulnrichment program scores newer CVEs (~2024 onwards) plus selected older critical ones. Use the EPSS probability + KEV status to triage instead.
CVSS vector breakdown
Exploitability - how they get in
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Impact - what breaks
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
VECTORCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Lifecycle
  1. 08 Mar 2019Published to NVD
  2. 17 Jun 2026Last modified
Every entry is a recorded date - NVD publish/modify, CISA KEV add, public exploit disclosure. No inferred events.
Attack path
Full kill chain
→
◆

ATT&CK techniques

1

Techniques this CVE enables. Pills with a solid outline are high confidence - named directly in ATT&CK or Nuclei, or human-curated by CTID; the rest are inferred from the weakness type using MITRE's CVE Mapping Methodology and the CWE → CAPEC chain. Broad, generic-weakness guesses are filtered out. A small N× marks a technique that N independent sources agree on.

T1190 · Exploit Public-Facing Application
▤ Build a SIEM detection for these techniques
▤

CAPEC attack patterns

1

Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.

CAPEC-CAPEC-540 · Overread Buffers
⬡

Weakness Classification

CWE-125Out-of-bounds Read
CWE-787Out-of-bounds Write
CWE-788Access of Memory Location After End of Buffer
▤

Affected Products & Versions

1
uvnc ultravnc< 1.2.2.3
▤

Related CVEs

8
CVEs linked to this one by a shared weakness (CWE) or affected product - joins on data already in the engine, with the reason shown per row.
CVE-1999-0022 Local user gains root privileges via buffer overflow in rdist, via expstr() func... same CWE-125 HIGH CVE-1999-0029 root privileges via buffer overflow in ordist command on SGI IRIX systems. 1 same CWE-125 HIGH CVE-1999-0006 Buffer overflow in POP servers based on BSD/Qualcomm's qpopper allows remote att... 2 same CWE-125 CRITICAL CVE-2004-0183 TCPDUMP 3.8.1 and earlier allows remote attackers to cause a denial of service (... same CWE-125 CVE-2002-2227 Buffer underflow in ssldump 0.9b2 and earlier allows remote attackers to cause a... same CWE-787 CVE-2003-0870 Heap-based buffer overflow in Opera 7.11 and 7.20 allows remote attackers to exe... 1 same CWE-787 CVE-2003-1396 Heap-based buffer overflow in Opera 6.05 through 7.10 allows remote attackers to... 1 same CWE-787 CVE-2004-0398 Heap-based buffer overflow in the ne_rfc1036_parse date parsing function for the... same CWE-787
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Sigma Hunt Rules

2
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighSuspicious UltraVNC Execution
productmediumUse of UltraVNC Remote Access Software
⚑

Vendor Advisories

5
siemens-csafSSA-286838
siemens-csafSSA-940818
cisa-csafcisa-csaf-csaf_files-OT-white-2020-icsa-20-161-06
cisa-csafcisa-csaf-csaf_files-OT-white-2021-icsa-21-131-04
cisa-csafcisa-csaf-csaf_files-OT-white-2021-icsa-21-131-11
🔗

References & Sources

6
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://cert-portal.siemens.com/productcert/pdf/ssa-286838.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-927095.pdf
https://cert-portal.siemens.com/productcert/pdf/ssa-940818.pdf
https://ics-cert.kaspersky.com/advisories/klcert-advisories/2019/03/01/klcert-19-012-ultravnc-access-of-memory-location-after-end-of-buffer/
Third Party Advisory
https://us-cert.cisa.gov/ics/advisories/icsa-21-131-11
https://www.us-cert.gov/ics/advisories/icsa-20-161-06
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