Cloud Vulnerability DB
An open project to list all known cloud vulnerabilities and Cloud Service Provider security issues
Vulnerability DatabaseCVE-2025-5270
CVE-2025-5270:
Mozilla Firefox vulnerability analysis and mitigation
Overview
CVE-2025-5270 is a security vulnerability discovered in Mozilla Firefox versions prior to 139 where Server Name Indication (SNI) could be transmitted unencrypted even when encrypted DNS was enabled. The vulnerability was reported by researcher xiulou and was publicly disclosed on May 27, 2025 (Mozilla Advisory, NVD).
Technical details
The vulnerability is classified as CWE-319 (Cleartext Transmission of Sensitive Information) with a CVSS v3.1 base score of 7.5 (HIGH), and vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. The issue specifically involves the exposure of SNI (Server Name Indication) data in cleartext, potentially compromising the privacy benefits of encrypted DNS (CISA-ADP).
Impact
The vulnerability has been assessed with a low impact rating by Mozilla. The primary concern is the potential exposure of browsing metadata through unencrypted SNI transmission, which could allow network observers to see which websites users are attempting to visit, even when encrypted DNS is enabled (Mozilla Advisory, GBHackers).
Mitigation and workarounds
The vulnerability has been fixed in Firefox version 139. Users are advised to update to this version or later to mitigate the risk. No alternative workarounds have been publicly documented (Mozilla Advisory).
Additional resources
Source: This report was generated using AI
Free Vulnerability Assessment
Benchmark your Cloud Security Posture
Evaluate your cloud security practices across 9 security domains to benchmark your risk level and identify gaps in your defenses.
Get a personalized demo
Ready to see Wiz in action?
“Best User Experience I have ever seen, provides full visibility to cloud workloads.”
David EstlickCISO
“Wiz provides a single pane of glass to see what is going on in our cloud environments.”
Adam FletcherChief Security Officer
“We know that if Wiz identifies something as critical, it actually is.”
Greg PoniatowskiHead of Threat and Vulnerability Management