Improper input validation in Gnu Libidn2

CVE-2019-12290

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.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.030 (85.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-12290?
CVE-2019-12290 is a high-severity vulnerability in Gnu Libidn2, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2019-10-22.
How severe is CVE-2019-12290?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2019-12290 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.