What’s Vulnerable › Vulnerabilities
CVE-2019-18800
- Severity: high (CVSS 8.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.7% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2019-11-06 · updated 2026-06-17
- Weakness: CWE-311
Description
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.
Affected products
- Rakuten Viber: through 11.7.0.5
References
- https://thesamarkand.tumblr.com/post/188785277609/viber-messenger-remote-account-reset-0day
- https://thesamarkand.tumblr.com/post/188785277609/viber-messenger-remote-account-reset-0day
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