RHSA-2021:4116 - Security Advisory

Topic

An update for firefox is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability.

This update upgrades Firefox to version 91.3.0 ESR.

Security Fix(es):

• Mozilla: Use-after-free in HTTP2 Session object
• Mozilla: Memory safety bugs fixed in Firefox 94 and Firefox ESR 91.3
• Mozilla: iframe sandbox rules did not apply to XSLT stylesheets (CVE-2021-38503)
• Mozilla: Use-after-free in file picker dialog (CVE-2021-38504)
• Mozilla: Firefox could be coaxed into going into fullscreen mode without notification or warning (CVE-2021-38506)
• Mozilla: Opportunistic Encryption in HTTP2 could be used to bypass the Same-Origin-Policy on services hosted on other ports (CVE-2021-38507)
• Mozilla: Permission Prompt could be overlaid, resulting in user confusion and potential spoofing (CVE-2021-38508)
• Mozilla: Javascript alert box could have been spoofed onto an arbitrary domain (CVE-2021-38509)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, Firefox must be restarted for the changes to take effect.

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le

Fixes

• BZ - 2019621 - CVE-2021-38503 Mozilla: iframe sandbox rules did not apply to XSLT stylesheets
• BZ - 2019622 - CVE-2021-38504 Mozilla: Use-after-free in file picker dialog
• BZ - 2019624 - CVE-2021-38506 Mozilla: Firefox could be coaxed into going into fullscreen mode without notification or warning
• BZ - 2019625 - CVE-2021-38507 Mozilla: Opportunistic Encryption in HTTP2 could be used to bypass the Same-Origin-Policy on services hosted on other ports
• BZ - 2019626 - Mozilla: Use-after-free in HTTP2 Session object
• BZ - 2019627 - CVE-2021-38508 Mozilla: Permission Prompt could be overlaid, resulting in user confusion and potential spoofing
• BZ - 2019628 - CVE-2021-38509 Mozilla: Javascript alert box could have been spoofed onto an arbitrary domain
• BZ - 2019630 - Mozilla: Memory safety bugs fixed in Firefox 94 and Firefox ESR 91.3

CVEs

• CVE-2021-38503
• CVE-2021-38504
• CVE-2021-38506
• CVE-2021-38507
• CVE-2021-38508
• CVE-2021-38509
• CVE-2021-43534
• CVE-2021-43535

References

• https://access.redhat.com/security/updates/classification/#important