An issue was discovered in Oniguruma 6.x before 6.9.4_rc2. In the function gb18030_mbc_enc_len in file gb18030.c, a UChar pointer is dereferenced without checking if it passed the end of the matched string. This leads to a heap-based buffer over-read.
github.com/kkos/oniguruma/issues/163
github.com/kkos/oniguruma/releases/tag/v6.9.4_rc2
github.com/ManhNDd/CVE-2019-19203
github.com/tarantula-team/CVE-2019-19203
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