CVE-2021-43541

Mozilla: External protocol handler parameters were unescaped

When invoking protocol handlers for external protocols, a supplied parameter URL containing spaces was not properly escaped. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

CVSS 3.1 · 6.5 Medium EPSS 1.6% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 4 more

CVE-2021-43539

Mozilla: GC rooting failure when calling wasm instance methods

Failure to correctly record the location of live pointers across wasm instance calls resulted in a GC occurring within the call not tracing those live pointers. This could have led to a use-after-free causing a potentially exploitable crash. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

CVSS 3.1 · 8.8 High EPSS 1.7% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 4 more

CVE-2021-43538

Mozilla: Missing fullscreen and pointer lock notification when requesting both

By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

CVSS 3.1 · 4.3 Medium EPSS 1.2% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 4 more

CVE-2021-43537

Mozilla: Heap buffer overflow when using structured clone

An incorrect type conversion of sizes from 64bit to 32bit integers allowed an attacker to corrupt memory leading to a potentially exploitable crash. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

CVSS 3.1 · 8.8 High EPSS 2.1% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 4 more

CVE-2021-43536

Mozilla: URL leakage when navigating while executing asynchronous function

Under certain circumstances, asynchronous functions could have caused a navigation to fail but expose the target URL. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

CVSS 3.1 · 6.5 Medium EPSS 1.7% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 4 more

CVE-2021-43535

Mozilla: Use-after-free in HTTP2 Session object

A use-after-free could have occured when an HTTP2 session object was released on a different thread, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 93, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 8.8 High EPSS 1.1% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more

CVE-2021-43534

Mozilla: Memory safety bugs fixed in Firefox 94 and Firefox ESR 91.3

Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox ESR 91.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 8.8 High EPSS 1.2% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more

CVE-2021-38510

Mozilla: Download Protections were bypassed by .inetloc files on Mac OS

The executable file warning was not presented when downloading .inetloc files, which, due to a flaw in Mac OS, can run commands on a user's computer.*Note: This issue only affected Mac OS operating systems. Other operating systems are unaffected.*. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 8.8 High EPSS 1.0% KEV · Not listed

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Apple Mozilla

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Macos Firefox Firefox Esr and 1 more

CVE-2021-38509

Mozilla: Javascript alert box could have been spoofed onto an arbitrary domain

Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 4.3 Medium EPSS 1.8% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more

CVE-2021-38508

Mozilla: Permission Prompt could be overlaid, resulting in user confusion and potential spoofing

By displaying a form validity message in the correct location at the same time as a permission prompt (such as for geolocation), the validity message could have obscured the prompt, resulting in the user potentially being tricked into granting the permission. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 4.3 Medium EPSS 1.6% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more

CVE-2021-38507

Mozilla: Opportunistic Encryption in HTTP2 could be used to bypass the Same-Origin-Policy on services hosted on other ports

The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a connection to be transparently upgraded to TLS while retaining the visual properties of an HTTP connection, including being same-origin with unencrypted connections on port 80. However, if a second encrypted port on the same IP address (e.g. port 8443) did not opt-in to opportunistic encryption; a network attacker could forward a connection from the browser to port 443 to port 8443, causing the browser to treat the content of port 8443 as same-origin with HTTP. This was resolved by disabling the Opportunistic Encryption feature, which had low usage. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more

CVE-2021-38506

Mozilla: Firefox could be coaxed into going into fullscreen mode without notification or warning

Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 4.3 Medium EPSS 1.5% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more

CVE-2021-38505

Mozilla: Windows 10 Cloud Clipboard may have recorded sensitive user data

Microsoft introduced a new feature in Windows 10 known as Cloud Clipboard which, if enabled, will record data copied to the clipboard to the cloud, and make it available on other computers in certain scenarios. Applications that wish to prevent copied data from being recorded in Cloud History must use specific clipboard formats; and Firefox before versions 94 and ESR 91.3 did not implement them. This could have caused sensitive data to be recorded to a user's Microsoft account. *This bug only affects Firefox for Windows 10+ with Cloud Clipboard enabled. Other operating systems are unaffected.*. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 6.5 Medium EPSS 1.1% KEV · Not listed

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Microsoft Mozilla

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Windows 10 Firefox Firefox Esr and 1 more

CVE-2021-38504

Mozilla: Use-after-free in file picker dialog

When interacting with an HTML input element's file picker dialog with webkitdirectory set, a use-after-free could have resulted, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 8.8 High EPSS 1.8% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more

CVE-2021-38503

Mozilla: iframe sandbox rules did not apply to XSLT stylesheets

The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such as executing scripts or navigating the top-level frame. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

CVSS 3.1 · 10.0 Critical EPSS 4.1% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more

CVE-2021-38501

Mozilla: Memory safety bugs fixed in Firefox 93 and Firefox ESR 91.2

Mozilla developers reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.

CVSS 3.1 · 8.8 High EPSS 1.0% KEV · Not listed

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Mozilla Redhat

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Firefox Firefox Esr Thunderbird and 2 more

CVE-2021-38500

Mozilla: Memory safety bugs fixed in Firefox 93, Firefox ESR 78.15, and Firefox ESR 91.2

Mozilla developers reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 78.15, Thunderbird < 91.2, Firefox ESR < 91.2, Firefox ESR < 78.15, and Firefox < 93.

CVSS 3.1 · 8.8 High EPSS 1.3% KEV · Not listed

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Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more

CVE-2021-38498

Mozilla: Use-after-free of nsLanguageAtomService object

During process shutdown, a document could have caused a use-after-free of a languages service object, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.

CVSS 3.1 · 7.5 High EPSS 1.5% KEV · Not listed

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Mozilla Redhat

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Firefox Firefox Esr Thunderbird and 2 more

CVE-2021-38497

Mozilla: Validation message could have been overlaid on another origin

Through use of reportValidity() and window.open(), a plain-text validation message could have been overlaid on another origin, leading to possible user confusion and spoofing attacks. This vulnerability affects Firefox < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.

CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed

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Mozilla Redhat

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Firefox Firefox Esr Thunderbird and 2 more

CVE-2021-38496

Mozilla: Use-after-free in MessageTask

During operations on MessageTasks, a task may have been removed while it was still scheduled, resulting in memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.15, Thunderbird < 91.2, Firefox ESR < 91.2, Firefox ESR < 78.15, and Firefox < 93.

CVSS 3.1 · 8.8 High EPSS 1.7% KEV · Not listed

Vendors

Debian Mozilla Redhat

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Debian Linux Firefox Firefox Esr and 3 more