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.
https://github.com/kkos/oniguruma/issues/163
https://github.com/kkos/oniguruma/releases/tag/v6.9.4_rc2
https://github.com/ManhNDd/CVE-2019-19203
Source: MITRE
Published: 2019-11-21
Updated: 2020-02-18
Type: CWE-125
Base Score: 5
Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P
Impact Score: 2.9
Exploitability Score: 10
Severity: MEDIUM
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Impact Score: 3.6
Exploitability Score: 3.9
Severity: HIGH