CVE-2019-12290

high

Description

GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2 when converting A-labels to U-labels. This makes it possible in some circumstances for one domain to impersonate another. By creating a malicious domain that matches a target domain except for the inclusion of certain punycoded Unicode characters (that would be discarded when converted first to a Unicode label and then back to an ASCII label), arbitrary domains can be impersonated.

References

https://gitlab.com/libidn/libidn2/commit/241e8f486134793cb0f4a5b0e5817a97883401f5

https://gitlab.com/libidn/libidn2/commit/614117ef6e4c60e1950d742e3edf0a0ef8d389de

https://gitlab.com/libidn/libidn2/merge_requests/71

https://usn.ubuntu.com/4168-1/

Details

Source: MITRE

Published: 2019-10-22

Updated: 2019-10-29

Type: CWE-20

Risk Information

CVSS v2

Base Score: 5

Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N

Impact Score: 2.9

Exploitability Score: 10

Severity: MEDIUM

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Impact Score: 3.6

Exploitability Score: 3.9

Severity: HIGH