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 heap out-of-bounds write occurs in bitset_set_range() during regular expression compilation due to an uninitialized variable from an incorrect state transition. An incorrect state transition in parse_char_class() could create an execution path that leaves a critical local variable uninitialized until it's used as an index, resulting in an out-of-bounds write memory corruption. Upstream bug: https://github.com/kkos/oniguruma/issues/60 Upstream patch: https://github.com/kkos/oniguruma/commit/3b63d12038c8d8fc278e81c942fa9bec7c704c8b
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]
Note also the second upstream patch: https://github.com/kkos/oniguruma/commit/ddbf55698b5f7ffdfa737b0b8e0079af1fdd7cb1
The attack demonstrated here gives very limited control - it looks like in the best case, up to 8 bits in a range determined by uninitialised (stack) data can be set to 1.
Ruby is not vulnerable according to upstream: ~~~ > CVE-2017-9228 https://github.com/kkos/oniguruma/issues/60 not affected. % ruby <<'END' str = [ 0xc7, 0xd6, 0xfe, 0xea, 0xe0, 0xe2, 0x00 ].pack('c*') pattern = "\x5b\x5c\x48\x2d\xb0\x30\x8d\x30\x2a\x5b\x5d\x20\x20\x5d" + "\xf9\x54\x00\x7f\x5c\x63\xef\xef\xef\xef\x52\xf7\xf7\x52" + "\xf7\xeb\xeb\x70\x2b\xf7\x7b\x30\x2c\x32\x7d" re = Regexp.new(pattern.force_encoding('GB18030'), Regexp::IGNORECASE) re.match str.force_encoding('GB18030') END Traceback (most recent call last): 2: from -:5:in `<main>' 1: from -:5:in `new' -:5:in `initialize': too short control escape: /[\H-\x{B0308D30}*[] ]\x{F954}\x00\x7F\c\x{EFEF}\x{EFEF}R\x{F7F7}R\x{F7EB}\x{EB70}+\x{F77B}0,2}/i (RegexpError) ~~~
(In reply to Doran Moppert from comment #2) > Note also the second upstream patch: > > https://github.com/kkos/oniguruma/commit/ > ddbf55698b5f7ffdfa737b0b8e0079af1fdd7cb1 On Fedora, I submitted oniguruma-6.1.3-3.fc25 . oniguruma on F-26 and above already contains this fix. (F-24 is EOL)
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