CVE-2019-12290
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.23%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 3.23% probability · 88th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- gnu/libidn2
- Source
- cve@mitre.org
EPSS 3.2% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00008.html
- http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00009.html
- https://gitlab.com/libidn/libidn2/commit/241e8f486134793cb0f4a5b0e5817a97883401f5Patch, Third Party Advisory
- https://gitlab.com/libidn/libidn2/commit/614117ef6e4c60e1950d742e3edf0a0ef8d389deThird Party Advisory
- https://gitlab.com/libidn/libidn2/merge_requests/71Patch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UFT76Y7OSGPZV3EBEHD6ISVUM3DLARM/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KXDKYWFV6N2HHVSE67FFDM7G3FEL2ZNE/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ONG3GJRRJO35COPGVJXXSZLU4J5Y42AT/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RSI4TI2JTQWQ3YEUX5X36GTVGKO4QKZ5/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U6ZXL2RDNQRAHCMKWPOMJFKYJ344X4HL/
- https://security.gentoo.org/glsa/202003-63
- https://usn.ubuntu.com/4168-1/
- http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00008.html
- http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00009.html
- https://gitlab.com/libidn/libidn2/commit/241e8f486134793cb0f4a5b0e5817a97883401f5Patch, Third Party Advisory
- https://gitlab.com/libidn/libidn2/commit/614117ef6e4c60e1950d742e3edf0a0ef8d389deThird Party Advisory
- https://gitlab.com/libidn/libidn2/merge_requests/71Patch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UFT76Y7OSGPZV3EBEHD6ISVUM3DLARM/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KXDKYWFV6N2HHVSE67FFDM7G3FEL2ZNE/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ONG3GJRRJO35COPGVJXXSZLU4J5Y42AT/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RSI4TI2JTQWQ3YEUX5X36GTVGKO4QKZ5/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U6ZXL2RDNQRAHCMKWPOMJFKYJ344X4HL/
- https://security.gentoo.org/glsa/202003-63
- https://usn.ubuntu.com/4168-1/
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.