CVE-2009-0388
CWE-189Published: February 4, 2009· Updated: Jun 16, 2026
Official Description
Multiple integer signedness errors in (1) UltraVNC 1.0.2 and 1.0.5 and (2) TightVnc 1.3.9 allow remote VNC servers to cause a denial of service (heap corruption and application crash) or possibly execute arbitrary code via a large length value in a message, related to the (a) ClientConnection::CheckBufferSize and (b) ClientConnection::CheckFileZipBufferSize functions in ClientConnection.cpp.
Technical Analysis
CVE-2009-0388 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A proof-of-concept (PoC) exploit exists for CVE-2009-0388. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (20)
Quick Facts
Related CVEs (CWE-189)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2009-0388 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts