Red Hat Bugzilla – Bug 1466730
CVE-2017-9224 oniguruma: Out-of-bounds stack read in match_at() during regular expression searching
Last modified: 2018-04-13 18:26:35 EDT
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.
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
% 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)
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 ...