An issue was discovered in Oniguruma 6.x before 6.9.4_rc2. In the function fetch_interval_quantifier (formerly known as fetch_range_quantifier) in regparse.c, PFETCH is called without checking PEND. This leads to a heap-based buffer over-read.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-19204
• kkos/oniguruma#162
• https://github.com/ManhNDd/CVE-2019-19204
• https://github.com/kkos/oniguruma/releases/tag/v6.9.4_rc2
• https://github.com/tarantula-team/CVE-2019-19204
• https://lists.debian.org/debian-lts-announce/2019/12/msg00002.html
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NO267PLHGYZSWX3XTRPKYBKD4J3YOU5V/
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/V3MBNW6Z4DOXSCNWGBLQ7OA3OGUJ44WL/
• https://usn.ubuntu.com/4460-1/