CVE-2019-20838: High severity Apple macOS Big Sur vulnerability

Published Jun 15, 2020
·
Updated

A vulnerability was found in libpcre in PCRE before 8.43 allows a subject buffer over-read in JIT when UTF is disabled, and \X or \R has more than one fixed quantifier, a related issue to CVE-2019-20454.

References: https://bugs.gentoo.org/717920 https://www.pcre.org/original/changelog.txt

Other sources

PCRE is vulnerable to a denial of service, caused by a buffer over-read in JIT. By sending a specially-crafted request, a remote attacker could exploit this vulnerability to cause the application to crash.

— IBM

PCRE. Multiple issues were addressed by updating to version 8.44.

Screen Sharing. Multiple issues were addressed by updating to version 8.44.

Credit

CVE-2019-20838, CVE-2020-14155

Affected Software

13 affected componentsFixes available
redhat/pcre<8.43
8.43
Apple macOS Big Sur<11.0.1
11.0.1
Apple macOS Big Sur<11.2
11.2
Apple Catalina
macOS Mojave
IBM QRadar SIEM<=7.5.0 GA
IBM QRadar SIEM<=7.4.3 GA - 7.4.3 FP4
IBM QRadar SIEM<=7.3.3 GA - 7.3.3 FP10
pcre pcre<8.43
macOS<11.0.1
Splunk Universal Forwarder>=8.2.0<8.2.12
Splunk Universal Forwarder>=9.0.0<9.0.6
Splunk Universal Forwarder=9.1.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Apple macOS to a version that resolves this vulnerability.

    Fixed in 11.0.1
  2. Upgrade

    Upgrade Apple macOS to a version that resolves this vulnerability.

    Fixed in 11.2
  3. Upgrade

    Upgrade redhat/pcre to a version that resolves this vulnerability.

    Fixed in 8.43
  4. Upgrade

    Upgrade libpcre (PCRE) to a version that resolves this vulnerability.

    Fixed in 8.44
  5. Compensating control

    Mitigate the PCRE denial-of-service exposure by protecting applications that use PCRE/JIT from remote attackers sending specially-crafted requests until the libpcre update to 8.44 is applied.

Event History

Jun 15, 2020
CVE Published
via MITRE·04:50 PM
Data Sourced
via MITRE·04:50 PM
Description
Jun 18, 2020
Data Sourced
via Red Hat·11:26 AM
DescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is CVE-2019-20838?

CVE-2019-20838 is a vulnerability in PCRE that can be exploited by a remote attacker to cause a denial of service by crashing the application.

2

What is the severity of CVE-2019-20838?

The severity of CVE-2019-20838 is high with a CVSS score of 7.5.

3

Which software versions are affected by CVE-2019-20838?

PCRE version 8.43 and earlier, Apple macOS Big Sur up to 11.2, Apple Catalina, Apple Mojave, IBM QRadar SIEM up to 7.5.0 GA, and IBM QRadar Vulnerability Manager up to 7.3.3 GA are affected by CVE-2019-20838.

4

How can I fix CVE-2019-20838?

Update to PCRE version 8.44, macOS Big Sur 11.0.1 or later, IBM QRadar SIEM 7.5.0 GA or later, or IBM QRadar Vulnerability Manager 7.3.3 GA or later to fix CVE-2019-20838.

5

Where can I find more information about CVE-2019-20838?

You can find more information about CVE-2019-20838 on the following references: [Apple Support](https://support.apple.com/en-us/HT212147), [Red Hat Security](https://access.redhat.com/security/cve/CVE-2019-20454), and [Gentoo Bugs](https://bugs.gentoo.org/717920).

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