CVE-2017-7781

Severity: medium (CVSS 5.9 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2018-06-11 · updated 2026-06-17

Description

An error occurs in the elliptic curve point addition algorithm that uses mixed Jacobian-affine coordinates where it can yield a result "POINT_AT_INFINITY" when it should not. A man-in-the-middle attacker could use this to interfere with a connection, resulting in an attacked party computing an incorrect shared secret. This vulnerability affects Firefox < 55.

Affected products

Mozilla Firefox: before 55.0 — fixed in 55.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 55.0. Check the vendor advisory for mitigations.

References

http://www.securityfocus.com/bid/100383
http://www.securitytracker.com/id/1039124
https://bugzilla.mozilla.org/show_bug.cgi?id=1352039
https://www.mozilla.org/security/advisories/mfsa2017-18/
http://www.securityfocus.com/bid/100383
http://www.securitytracker.com/id/1039124
https://bugzilla.mozilla.org/show_bug.cgi?id=1352039
https://www.mozilla.org/security/advisories/mfsa2017-18/

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