Affected: Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird

On some systems—depending on the graphics settings and drivers—it was possible to force an out-of-bounds read and leak memory data into the images created on the canvas element. This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5.

Affected: Ubuntu:20.04:LTS: firefox

Multiple security issues were discovered in Firefox. If a user were tricked into opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information across domains, or execute arbitrary code. (CVE-2023-6206, CVE-2023-6210, CVE-2023-6211, CVE-2023-6212, CVE-2023-6213)

It was discovered that Firefox did not properly manage memory when images were created on the canvas element. An attacker could potentially exploit this issue to obtain sensitive information. (CVE-2023-6204)

It discovered that Firefox incorrectly handled certain memory when using a MessagePort. An attacker could potentially exploit this issue to cause a denial of service. (CVE-2023-6205)

It discovered that Firefox incorrectly did not properly manage ownership in ReadableByteStreams. An attacker could potentially exploit this issue to cause a denial of service. (CVE-2023-6207)

It discovered that Firefox incorrectly did not properly manage copy operations when using Selection API in X11. An attacker could potentially exploit this issue to obtain sensitive information. (CVE-2023-6208)

Rachmat Abdul Rokhim discovered that Firefox incorrectly handled parsing of relative URLS starting with "///". An attacker could potentially exploit this issue to cause a denial of service. (CVE-2023-6209)