CVE-2019-25600 | UltraVNC Viewer 1.2.2.4 VNC Server out-of-bounds write (Exploit 46702 / EDB-46702)

VDB-352436 · CVE-2019-25600 · EXPLOIT 46702 ULTRAVNC VIEWER 1.2.2.4 VNC SERVER OUT-OF-BOUNDS WRITE HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 5.2 $0-$5k 1.53+ Summaryinfo A vulnerability classified as critical was found in UltraVNC Viewer 1.2.2.4. The impacted element is an unknown function. Such manipulation of the argument VNC Server leads to out-of-bounds write. This vulnerability is documented as CVE-2019-25600. The attack can be executed remotely. Additionally, an exploit exists. Detailsinfo A vulnerability was found in UltraVNC Viewer 1.2.2.4 and classified as problematic. Affected by this issue is an unknown function. The manipulation of the argument VNC Server with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is availability. CVE summarizes: UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer. The weakness was released by Victor Mondragón as 46702. The advisory is shared for download at exploit-db.com. This vulnerability is handled as CVE-2019-25600 since 03/22/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. Technical details as well as a public exploit are known. The exploit is available at exploit-db.com. It is declared as proof-of-concept. There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product. The vulnerability is also documented in the vulnerability database at Exploit-DB (46702). Productinfo Type Connectivity Software Vendor UltraVNC Name Viewer Version 1.2.2.4 License open-source CPE 2.3info 🔒 CPE 2.2info 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA CVSS-B Score: 🔒 CNA CVSS-BT Score: 🔒 CNA Vector: 🔒 CVSSv3info VulDB Meta Base Score: 5.4 VulDB Meta Temp Score: 5.2 VulDB Base Score: 4.3 VulDB Temp Score: 3.9 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 6.5 CNA Vector (VulnCheck): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Out-of-bounds write CWE: CWE-787 / CWE-119 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Access: Public Status: Proof-of-Concept Download: 🔒 Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Exploit-DB: 🔒 Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: no mitigation known Status: 🔍 0-Day Time: 🔒 Timelineinfo 03/22/2026 Advisory disclosed 03/22/2026 +0 days CVE reserved 03/22/2026 +0 days VulDB entry created 03/22/2026 +0 days VulDB entry last update Sourcesinfo Advisory: 46702 Researcher: Victor Mondragón Status: Not defined CVE: CVE-2019-25600 (🔒) GCVE (CVE): GCVE-0-2019-25600 GCVE (VulDB): GCVE-100-352436 scip Labs: https://www.scip.ch/en/?labs.20161013 Entryinfo Created: 03/22/2026 15:50 Changes: 03/22/2026 15:50 (81) Complete: 🔍 Cache ID: 99:2B2:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸