CVE-2021-23987

Los desarrolladores y miembros de la comunidad de Mozilla informaron de fallos de seguridad de memoria presentes en Firefox 86 y Firefox ESR 78.8. Algunos de estos fallos mostraban evidencias de corrupción de memoria y suponemos que con suficiente esfuerzo algunos de ellos podrían haber sido explotados para ejecutar código arbitrario. Esta vulnerabilidad afecta a Firefox ESR versiones anteriores a 78.9, Firefox versiones anteriores a 87 y Thunderbird versiones anteriores a 78.9

The Mozilla Foundation Security Advisory describes this issue as: Mozilla developers and community members reported memory safety bugs present in Firefox 86 and Firefox ESR 78.8. 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.

USN-4995-1 fixed vulnerabilities in Thunderbird. This update provides the corresponding updates for Ubuntu 18.04 LTS. Multiple security issues were discovered in Thunderbird. If a user were tricked into opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, spoof the UI, bypass security restrictions, or execute arbitrary code. It was discovered that extensions could open popup windows with control of the window title in some circumstances. If a user were tricked into installing a specially crafted extension, an attacker could potentially exploit this to spoof a website and trick the user into providing credentials. Multiple security issues were discovered in Thunderbird's OpenPGP integration. If a user were tricked into importing a specially crafted key in some circumstances, an attacker could potentially exploit this to cause a denial of service or confuse the user. A use-after-free was discovered when Responsive Design Mode was enabled. If a user were tricked into opening a specially crafted website with Responsive Design Mode enabled, an attacker could potentially exploit this to cause a denial of service, or execute arbitrary code. It was discovered that Thunderbird mishandled ftp URLs with encoded newline characters. If a user were tricked into clicking on a specially crafted link, an attacker could potentially exploit this to send arbitrary FTP commands. It was discovered that Thunderbird wrote signatures to disk and read them back during verification. A local attacker could potentially exploit this to replace the data with another signature file. It was discovered that Thunderbird might load an alternative OTR library. If a user were tricked into copying a specially crafted library to one of Thunderbird's search paths, an attacker could potentially exploit this to execute arbitrary code. It was discovered that secret keys imported into Thunderbird were stored unencrypted. A local attacker could potentially exploit this to obtain private keys. It was discovered that Thunderbird did not indicate when an inline signed or encrypted message contained additional unprotected parts. Various other issues were also addressed.