Vulnerability Description
Net::IDN::Punycode versions before 2.301 for Perl allow a heap buffer overflow via unchecked writes past the output buffer in encode_punycode. The XS backend builds the encoded label in the string buffer of the scalar it returns, sized from the input length. The loop that emits the digits of each code point checks for room before every write, but the write of the last digit of each round and the write of the terminating NUL do not, so an input whose encoded form fills the buffer writes past its end. Only the XS backend is affected. Encoding an attacker-supplied string corrupts the heap.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://github.com/robrwo/Net-IDN-Encode/commit/9a3ba07f15d22c0347eefee9625b012c
- https://metacpan.org/release/CFAERBER/Net-IDN-Encode-2.301/changes
- https://rt.cpan.org/Ticket/Display.html?id=118924
- http://www.openwall.com/lists/oss-security/2026/09/22/10
FAQ
What is CVE-2016-15059?
CVE-2016-15059 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Net::IDN::Punycode versions before 2.301 for Perl allow a heap buffer overflow via unchecked writes past the output buffer in encode_punycode. The XS backend builds the encoded label in the string bu...
How severe is CVE-2016-15059?
CVE-2016-15059 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2016-15059?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.