Denial of service in PCRE2

1) Out-of-bounds read

EUVDB-ID: #VU29116

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-20454

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to perform denial of service (DoS) attack.

The vulnerability exists due to a boundary condition in the "do_extuni_no_utf in pcre2_jit_compile.c" file when the pattern X is JIT compiled and used to match specially crafted subjects in non-UTF mode. A remote attacker can trigger out-of-bounds read error and crash the affected application.

Mitigation

Install update from vendor's website.

Vulnerable software versions

PCRE2: 10.00 - 10.33

External links

http://bugs.exim.org/show_bug.cgi?id=2421
http://bugs.php.net/bug.php?id=78338
http://bugzilla.redhat.com/show_bug.cgi?id=1735494
http://security.gentoo.org/glsa/202006-16
http://vcs.pcre.org/pcre2?view=revision&revision=1092

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.