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 match_at() during regular expression searching. A logical error involving order of validation and access in match_at() could result in an out-of-bounds read from a stack buffer. Upstream bug: https://github.com/kkos/oniguruma/issues/57 Upstream patch: https://github.com/kkos/oniguruma/commit/690313a061f7a4fa614ec5cc8368b4f2284e059b
Created oniguruma tracking bugs for this issue: Affects: epel-7 [bug 1466750] Affects: fedora-all [bug 1466752] Created php tracking bugs for this issue: Affects: fedora-all [bug 1466751] Created ruby tracking bugs for this issue: Affects: fedora-all [bug 1466749] Created ruby193-ruby tracking bugs for this issue: Affects: openshift-1 [bug 1466753]
Exploiting this flaw results in a single byte read beyond the end of the input string, which is stack-allocated in the reproducer but could plausibly also be heap-allocated. Information about the byte read may under some circumstances be leaked to the attacker, but their opportunity to control this or repeatedly exploit it to learn useful information is very small.
This is not vulnerable according to the upstream: ~~~ > CVE-2017-9224 https://github.com/kkos/oniguruma/issues/57 not affected. % ruby <<'END' str = [ 0xc7, 0xd6, 0xfe, 0xea, 0xe0, 0xe2, 0x00 ].pack('c*') input = [0xf1, 0x5c, 0x69, 0x53, 0x53, 0x53, 0x53, 0x3c, 0x30, 0x53, 0x59, 0x54, 0x52, 0x33, 0x7c, 0x2e, 0x5c, 0xe2, 0x48, 0x5c, 0x7a, 0x53, 0x00, 0x06, 0x00, 0x00, 0x27, 0x19, 0x00, 0x54, 0x52, 0x54, 0x52, 0x33, 0x7c, 0x2e, 0x53, 0xe2, 0x48].pack('c*') re = Regexp.new(input.force_encoding('Shift_JIS'), Regexp::IGNORECASE) re.match str.force_encoding('Shift_JIS') END Traceback (most recent call last): 1: from -:8:in `<main>' -:8:in `match': invalid byte sequence in Shift_JIS (ArgumentError) ~~~
(In reply to Vít Ondruch from comment #3) Speaking in Ruby context ...
This issue has been addressed in the following products: Red Hat Software Collections for Red Hat Enterprise Linux 6 Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS Red Hat Software Collections for Red Hat Enterprise Linux 7 Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS Via RHSA-2018:1296 https://access.redhat.com/errata/RHSA-2018:1296