SB2020111838 - Ubuntu update for firefox
Published: November 18, 2020 Updated: April 23, 2025
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 15 secuirty vulnerabilities.
1) Buffer overflow (CVE-ID: CVE-2020-26952)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content. The incorrect bookkeeping of functions inlined during JIT compilation when handling out-of-memory errors can trigger memory corruption and allow remote code execution.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
2) Use-after-free (CVE-ID: CVE-2020-26959)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error within the WebRequestService component during browser shutdown. A remote attacker can create a specially crafted web page, trick the victim into visiting it, force the victim to shutdown the browser, trigger a use-after-free error and execute arbitrary code on the system.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
3) Buffer overflow (CVE-ID: CVE-2020-26969)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content. A remote attacker can create a specially crafted web page, trick the victim into opening it, trigger memory corruption and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
4) Use-after-free (CVE-ID: CVE-2020-26960)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error within nsTArray implementation. If the Compact() method was called on an nsTArray, the array could have been reallocated without updating other pointers. A remote attacker can create a specially crafted web page, trick the victim into visiting it, trigger a use-after-free error and execute arbitrary code on the system.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
5) Improperly implemented security check for standard (CVE-ID: CVE-2020-26961)
The vulnerability allows a remote attacker to perform a DNS rebinding attack.
The vulnerability exists due to the way Firefox filters IPv4 mapped IP addresses. When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges from the responses as these do not make sense coming from a DoH resolver. However when an IPv4 address was mapped through IPv6, these addresses were erroneously let through, leading to a potential DNS Rebinding attack.
6) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2020-26958)
The vulnerability allows a remote attacker to escalate privileges on the system.
The vulnerability exists due Firefox does not block execution of scripts with incorrect MIME types when the response was intercepted and cached through a ServiceWorker. A remote attacker can exploit this behavior to perform a cross-site script inclusion vulnerability or bypass implemented Content Security Policy restrictions.
7) Resource management error (CVE-ID: CVE-2020-26967)
The vulnerability allows a remote attacker to introduce an unexpected behavior.
The vulnerability exists due to improper management of internal resources within Mutation Observers. When listening for page changes with a Mutation Observer, a malicious web page could confuse Firefox Screenshots into interacting with elements other than those that it injected into the page. This would lead to internal errors and unexpected behavior in the Screenshots code.
8) Information disclosure (CVE-ID: CVE-2020-26965)
The vulnerability allows a local user to gain access to potentially sensitive information.
The vulnerability exists due to the way software keyboards are handled by the Firefox. Some websites have a feature "Show Password" where clicking a button will change a password field into a textbook field, revealing the typed password. If, when using a software keyboard that remembers user input, a user typed their password and used that feature, the type of the password field was changed, resulting in a keyboard layout change and the possibility for the software keyboard to remember the typed password.
A local user leverage this behavior to gain access to passwords, stored by software keyboards.
9) Buffer overflow (CVE-ID: CVE-2020-26968)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content. A remote attacker can create a specially crafted web page, trick the victim into opening it, trigger memory corruption and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
10) Insufficient UI Warning of Dangerous Operations (CVE-ID: CVE-2020-26953)
The vulnerability allows a remote attacker to perform spoofing attack.
The vulnerability exists due to the way under certain conditions Firefox enters the fullscreen mode without displaying UI notification. A remote attacker can perform a phishing attack.
11) Improper Interaction Between Multiple Correctly-Behaving Entities (CVE-ID: CVE-2020-26962)
The vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists in the way cross-origin iframes supported login autofill is being performed. Cross-origin iframes that contained a login form could have been recognized by the login autofill service and populated. This could have been used in clickjacking attacks, as well as be read across partitions in dynamic first party isolation.
12) Input validation error (CVE-ID: CVE-2020-26951)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to insufficient validation of user-supplied input. A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization. An attacker already capable of exploiting an XSS vulnerability in privileged internal pages could have used this attack to bypass the built-in sanitizer.
13) Universal cross-site scripting (CVE-ID: CVE-2020-26956)
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data. In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
14) Resource management error (CVE-ID: CVE-2020-26963)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to improper management of internal resources. Repeated calls to the history and location interfaces could have been
used to hang the browser.
15) Origin validation error (CVE-ID: CVE-2020-16012)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to the way browser handles requests to cross-origin images. When drawing a transparent image on top of an unknown cross-origin image, the Skia library drawImage
function takes a variable amount of time depending on the content of the
underlying image. This results in cross-origin information
exposure of image content through timing side-channel attacks.
Remediation
Install update from vendor's website.