An issue was discovered in Oniguruma 6.2.0, as used in Oniguruma-mod in Ruby through 2.4.1 and mbstring in PHP through 7.1.5. A stack out-of-bounds read occurs in mbc_enc_len() during regular expression searching. Invalid handling of reg->dmin in forward_search_range() could result in an invalid pointer dereference, as an out-of-bounds read from a stack buffer.

References

• https://nvd.nist.gov/vuln/detail/CVE-2017-9227
• kkos/oniguruma#58
• kkos/oniguruma@9690d3a
• https://access.redhat.com/errata/RHSA-2018:1296
• http://www.securityfocus.com/bid/100538