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 (12)
Core 12
Core References
Patch, Third Party Advisory x_refsource_misc
https://gitlab.com/libidn/libidn2/merge_requests/71
Patch, Third Party Advisory x_refsource_misc
https://gitlab.com/libidn/libidn2/commit/241e8f486134793cb0f4a5b0e5817a97883401f5
Third Party Advisory x_refsource_confirm
https://gitlab.com/libidn/libidn2/commit/614117ef6e4c60e1950d742e3edf0a0ef8d389de
Vendor Advisory vendor-advisory
x_refsource_ubuntu
https://usn.ubuntu.com/4168-1/
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U6ZXL2RDNQRAHCMKWPOMJFKYJ344X4HL/
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UFT76Y7OSGPZV3EBEHD6ISVUM3DLARM/
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KXDKYWFV6N2HHVSE67FFDM7G3FEL2ZNE/
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RSI4TI2JTQWQ3YEUX5X36GTVGKO4QKZ5/
Mailing List vendor-advisory
x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00009.html
Mailing List vendor-advisory
x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00008.html
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ONG3GJRRJO35COPGVJXXSZLU4J5Y42AT/
Third Party Advisory vendor-advisory
x_refsource_gentoo
https://security.gentoo.org/glsa/202003-63
Scores
CVSS v3
7.5
EPSS
0.0357
EPSS Percentile
87.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Details
CWE
CWE-20
Status
published
Products (1)
gnu/libidn2
< 2.2.0
Published
Oct 22, 2019
Tracked Since
Feb 18, 2026