A libonig security update has been released for Debian GNU/Linux 9 LTS to address several vulnerabilities in the Oniguruma regular expressions library.

SECURITY: DLA 2431-1: libonig security update

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Debian LTS Advisory DLA-2431-1 debian-lts@lists.debian.org
  https://www.debian.org/lts/security/ Markus Koschany
November 05, 2020   https://wiki.debian.org/LTS
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Package : libonig
Version : 6.1.3-2+deb9u1
CVE ID : CVE-2019-13224 CVE-2019-16163 CVE-2019-19012
CVE-2019-19203 CVE-2019-19204 CVE-2019-19246
CVE-2020-26159
Debian Bug : 931878 939988 944959 945312 945313 946344 972113

Several vulnerabilities were discovered in the Oniguruma regular
expressions library, notably used in PHP mbstring.

CVE-2019-13224

A use-after-free in onig_new_deluxe() in regext.c allows
attackers to potentially cause information disclosure, denial of
service, or possibly code execution by providing a crafted regular
expression. The attacker provides a pair of a regex pattern and a
string, with a multi-byte encoding that gets handled by
onig_new_deluxe().

CVE-2019-16163

Oniguruma allows Stack Exhaustion in regcomp.c because of recursion
in regparse.c.

CVE-2019-19012

An integer overflow in the search_in_range function in regexec.c in
Onigurama leads to an out-of-bounds read, in which the offset of
this read is under the control of an attacker. (This only affects
the 32-bit compiled version). Remote attackers can cause a
denial-of-service or information disclosure, or possibly have
unspecified other impact, via a crafted regular expression.

CVE-2019-19203

An issue was discovered in Oniguruma. 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.

CVE-2019-19204

An issue was discovered in Oniguruma. 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.

CVE-2019-19246

Oniguruma has a heap-based buffer over-read in str_lower_case_match
in regexec.c.

CVE-2020-26159

In Oniguruma an attacker able to supply a regular expression for
compilation may be able to overflow a buffer by one byte in
concat_opt_exact_str in src/regcomp.c

For Debian 9 stretch, these problems have been fixed in version
6.1.3-2+deb9u1.

We recommend that you upgrade your libonig packages.

For the detailed security status of libonig please refer to
its security tracker page at:
  https://security-tracker.debian.org/tracker/libonig

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at:   https://wiki.debian.org/LTS