CVE Vulnerabilities

CVE-2025-0996

Insufficient Visual Distinction of Homoglyphs Presented to User

Published: Feb 15, 2025 | Modified: Feb 15, 2025
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

Inappropriate implementation in Browser UI in Google Chrome on Android prior to 133.0.6943.98 allowed a remote attacker to spoof the contents of the Omnibox (URL bar) via a crafted HTML page. (Chromium security severity: High)

Weakness

The product displays information or identifiers to a user, but the display mechanism does not make it easy for the user to distinguish between visually similar or identical glyphs (homoglyphs), which may cause the user to misinterpret a glyph and perform an unintended, insecure action.

Affected Software

Name Vendor Start Version End Version
Chromium-browser Ubuntu upstream *

Extended Description

Some glyphs, pictures, or icons can be semantically distinct to a program, while appearing very similar or identical to a human user. These are referred to as homoglyphs. For example, the lowercase “l” (ell) and uppercase “I” (eye) have different character codes, but these characters can be displayed in exactly the same way to a user, depending on the font. This can also occur between different character sets. For example, the Latin capital letter “A” and the Greek capital letter “Α” (Alpha) are treated as distinct by programs, but may be displayed in exactly the same way to a user. Accent marks may also cause letters to appear very similar, such as the Latin capital letter grave mark “À” and its equivalent “Á” with the acute accent. Adversaries can exploit this visual similarity for attacks such as phishing, e.g. by providing a link to an attacker-controlled hostname that looks like a hostname that the victim trusts. In a different use of homoglyphs, an adversary may create a back door username that is visually similar to the username of a regular user, which then makes it more difficult for a system administrator to detect the malicious username while reviewing logs.

Potential Mitigations

  • Use a browser that displays Punycode for IDNs in the URL and status bars, or which color code various scripts in URLs.
  • Due to the prominence of homoglyph attacks, several browsers now help safeguard against this attack via the use of Punycode. For example, Mozilla Firefox and Google Chrome will display IDNs as Punycode if top-level domains do not restrict which characters can be used in domain names or if labels mix scripts for different languages.
  • Use an email client that has strict filters and prevents messages that mix character sets to end up in a user’s inbox.
  • Certain email clients such as Google’s GMail prevent the use of non-Latin characters in email addresses or in links contained within emails. This helps prevent homoglyph attacks by flagging these emails and redirecting them to a user’s spam folder.

References