CVE-2017-5120

CVE-2017-5120 is a medium-severity vulnerability in Google Chrome with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

Inappropriate use of www mismatch redirects in browser navigation in Google Chrome prior to 61.0.3163.79 for Mac, Windows, and Linux, and 61.0.3163.81 for Android, allowed a remote attacker to potentially downgrade HTTPS requests to HTTP via a crafted HTML page. In other words, Chrome could transmit cleartext even though the user had entered an https URL, because of a misdesigned workaround for cases where the domain name in a URL almost matches the domain name in an X.509 server certificate (but differs in the initial "www." substring).

Frequently asked questions

What is CVE-2017-5120?
Inappropriate use of www mismatch redirects in browser navigation in Google Chrome prior to 61.0.3163.79 for Mac, Windows, and Linux, and 61.0.3163.81 for Android, allowed a remote attacker to potentially downgrade HTTPS requests to HTTP via a crafted HTML page. In other words, Chrome could transmit cleartext even though the user had entered an https URL, because of a misdesigned workaround for cases where the domain name in a URL almost matches the domain name in an X.509 server certificate (but differs in the initial "www." substring).
How severe is CVE-2017-5120?
CVE-2017-5120 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2017-5120 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-5120?
CVE-2017-5120 primarily affects Google Chrome. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-5120?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-5120 published?
CVE-2017-5120 was published on 2017-10-27 and last updated on 2026-06-17.

References

Affected products (6)

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