HOMEVULNERABILITIESCVE-2019-20454
HIGH

CVE-2019-20454

CWE-125Published: February 14, 2020· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official Description

An out-of-bounds read was discovered in PCRE before 10.34 when the pattern \X is JIT compiled and used to match specially crafted subjects in non-UTF mode. Applications that use PCRE to parse untrusted input may be vulnerable to this flaw, which would allow an attacker to crash the application. The flaw occurs in do_extuni_no_utf in pcre2_jit_compile.c.

NVD Source

Technical Analysis

CVE-2019-20454 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

Fedora1 product(s)
fedora
pcre1 product(s)
pcre2
splunk1 product(s)
universal forwarder
Source: NVD CPE · 4 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=1735494
PATCHhttps://vcs.pcre.org/pcre2?view=revision&revision=1092
PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=1735494
PATCHhttps://vcs.pcre.org/pcre2?view=revision&revision=1092
ADVISORYhttps://bugs.exim.org/show_bug.cgi?id=2421
ADVISORYhttps://bugs.php.net/bug.php?id=78338
ADVISORYhttps://lists.debian.org/debian-lts-announce/2023/03/msg00014.html
ADVISORYhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OQRAHYHLRNMBTPR3KXVM27NSZP3KTOPI/
ADVISORYhttps://security.gentoo.org/glsa/202006-16
ADVISORYhttps://bugs.exim.org/show_bug.cgi?id=2421
ADVISORYhttps://bugs.php.net/bug.php?id=78338
ADVISORYhttps://lists.debian.org/debian-lts-announce/2023/03/msg00014.html
ADVISORYhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OQRAHYHLRNMBTPR3KXVM27NSZP3KTOPI/
ADVISORYhttps://security.gentoo.org/glsa/202006-16

All References (14)

→
https://bugs.exim.org/show_bug.cgi?id=2421Issue Tracking · Permissions Required · Third Party Advisory
→
https://bugs.php.net/bug.php?id=78338Exploit · Issue Tracking · Third Party Advisory
→
https://bugzilla.redhat.com/show_bug.cgi?id=1735494Issue Tracking · Patch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2023/03/msg00014.htmlMailing List · Third Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OQRAHYHLRNMBTPR3KXVM27NSZP3KTOPI/Mailing List · Third Party Advisory
→
https://security.gentoo.org/glsa/202006-16Third Party Advisory
→
https://vcs.pcre.org/pcre2?view=revision&revision=1092Broken Link · Patch
→
https://bugs.exim.org/show_bug.cgi?id=2421Issue Tracking · Permissions Required · Third Party Advisory
→
https://bugs.php.net/bug.php?id=78338Exploit · Issue Tracking · Third Party Advisory
→
https://bugzilla.redhat.com/show_bug.cgi?id=1735494Issue Tracking · Patch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2023/03/msg00014.htmlMailing List · Third Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OQRAHYHLRNMBTPR3KXVM27NSZP3KTOPI/Mailing List · Third Party Advisory
→
https://security.gentoo.org/glsa/202006-16Third Party Advisory
→
https://vcs.pcre.org/pcre2?view=revision&revision=1092Broken Link · Patch

Quick Facts

CVE IDCVE-2019-20454
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-125
CISA KEVNo
Affected3 vendor(s)
PublishedFeb 14, 2020

Related CVEs (CWE-125)

CVE-2021-21777
10.0
CVE-2021-41556
10.0
CVE-2017-14451
10.0
CVE-2009-2523
10.0
CVE-2013-0767
10.0
CVE-2023-26489
9.9

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2019-20454 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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