Security readout for executives and security teams
Plain-English summary
This issue affects Yandex Browser for Android versions before 21.3.0. A malicious site or link could make a deceptive internationalized domain name look like a trusted one, increasing phishing risk. The main business concern is credential or data theft through user deception, not direct device compromise.
Executive priority
Treat as a moderate mobile phishing risk. Prioritize remediation if Yandex Browser is used by staff with access to email, finance, admin portals, or customer data.
Technical view
CVE-2021-25262 is an IDN homograph vulnerability in Yandex Browser for Android before 21.3.0, mapped to CWE-116. CVSS 4.0 score is 6.9 with network attack vector, low complexity, no privileges, and required user interaction. Reported impact is high confidentiality impact only.
Likely exposure
Exposure is limited to Android users running Yandex Browser earlier than 21.3.0. Organizations without Yandex Browser in their mobile fleet likely have little direct exposure.
Exploitation context
The source bundle does not show KEV listing or active exploitation evidence. Practical abuse would likely depend on phishing or social engineering that persuades a user to visit or trust a deceptive domain.
Researcher notes
The affected-version evidence is sparse and slightly structured oddly: the description says prior to 21.3.0, while the affected object lists 21.3.0 with defaultStatus unaffected. Use the narrative description as the clearest boundary and verify against vendor data.
Mitigation direction
- Identify Android devices running Yandex Browser.
- Update Yandex Browser for Android to 21.3.0 or later.
- Use MDM controls to block outdated browser versions.
- Check Yandex guidance for any additional vendor-specific recommendations.
- Prioritize users with access to sensitive accounts or data.
Validation and detection
- Review MDM or endpoint inventory for Yandex Browser versions.
- Confirm no Android device runs Yandex Browser below 21.3.0.
- Check vulnerability scanner logic against the CVE description.
- Validate mobile browser allowlists or app compliance policies.
- Document exceptions for unmanaged or bring-your-own devices.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-116: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-25262 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.9 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
6.9MediumVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Source materials
- CVE List V5 sourceCVE List V5
- https://yandex.com/bugbounty/i/hall-of-fame-browser/CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Encoding or Escaping of Output
Improper Encoding or Escaping of Output represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.