Viber through 11.7.0.5 allows a remote attacker who can capture a victim's internet traffic to steal their Viber account, because not all Viber protocol traffic is encrypted. TCP data packet 9 on port 4244 from the victim's device contains cleartext information such as the device model and OS version, IMSI, and 20 bytes of udid in a binary format, which is located at offset 0x14 of this packet. Then, the attacker installs Viber on his device, initiates the registration process for any phone number, but doesn't enter a pin from SMS. Instead, he closes Viber. Next, the attacker rewrites his udid with the victim's udid, modifying the viber_udid file, which is located in the Viber preferences folder. (The udid is stored in a hexadecimal format.) Finally, the attacker starts Viber again and enters the pin from SMS.
Conclusion & alert: CVE-2019-18800 is rated High Exploit Risk (75.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.44%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.21% over the last day, indicating growing attacker interest. Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.23% | 1.44% | +1.21% |
| 2 | 2025-03-17 | 3.87% | 0.23% | -3.63% |
| 3 | 2024-12-17 | — | 3.87% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | [email protected] |
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| URL | Tags |
|---|---|
| https://thesamarkand.tumblr.com/post/188785277609/viber-messenger-remote-account-reset-0day | Exploit Third Party Advisory |