What’s Vulnerable › Vulnerabilities

CVE-2021-23253

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-01-11 · updated 2026-06-17

Description

Opera Mini for Android below 53.1 displays URL left-aligned in the address field. This allows a malicious attacker to craft a URL with a long domain name, e.g. www.safe.opera.com.attacker.com. With the URL being left-aligned, the user will only see the front part (e.g. www.safe.opera.com…) The exact amount depends on the phone screen size but the attacker can craft a number of different domains and target different phones. Starting with version 53.1 Opera Mini displays long URLs with the top-level domain label aligned to the right of the address field which mitigates the issue.

Affected products

• Opera Mini for Android: before 53.1 — fixed in 53.1

How to fix

Upgrade to a fixed version: Opera Mini for Android 53.1. Check the vendor advisory for mitigations.

References

• https://security.opera.com/address-bar-spoofing-in-opera-mini-opera-security-advisories/
• https://security.opera.com/address-bar-spoofing-in-opera-mini-opera-security-advisories/

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