Crossbeam is a set of tools for concurrent programming. In crossbeam-channel before version 0.4.4, the bounded channel incorrectly assumes that `Vec::from_iter` has allocated capacity that same as the number of iterator elements. `Vec::from_iter` does not actually guarantee that and may allocate extra memory. The destructor of the `bounded` channel reconstructs `Vec` from the raw pointer based on the incorrect assumes described above. This is unsound and causing deallocation with the incorrect capacity when `Vec::from_iter` has allocated different sizes with the number of iterator elements. This has been fixed in crossbeam-channel 0.4.4.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Crossbeam is a set of tools for concurrent programming. In crossbeam-channel before version 0.4.4, the     bounded channel incorrectly assumes that `Vec::from_iter` has allocated capacity that same as the number     of iterator elements. `Vec::from_iter` does not actually guarantee that and may allocate extra memory. The     destructor of the `bounded` channel reconstructs `Vec` from the raw pointer based on the incorrect assumes     described above. This is unsound and causing deallocation with the incorrect capacity when     `Vec::from_iter` has allocated different sizes with the number of iterator elements. This has been fixed     in crossbeam-channel 0.4.4. (CVE-2020-15254)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - Mozilla developers reported memory safety bugs present in Firefox 81. 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 < 82. (CVE-2020-15684)

  - Crossbeam is a set of tools for concurrent programming. In crossbeam-channel before version 0.4.4, the
    bounded channel incorrectly assumes that `Vec::from_iter` has allocated capacity that same as the number
    of iterator elements. `Vec::from_iter` does not actually guarantee that and may allocate extra memory. The
    destructor of the `bounded` channel reconstructs `Vec` from the raw pointer based on the incorrect assumes
    described above. This is unsound and causing deallocation with the incorrect capacity when
    `Vec::from_iter` has allocated different sizes with the number of iterator elements. This has been fixed
    in crossbeam-channel 0.4.4. (CVE-2020-15254)

  - If a valid external protocol handler was referenced in an image tag, the resulting broken image size could
    be distinguished from a broken image size of a non-existent protocol handler. This allowed an attacker to
    successfully probe whether an external protocol handler was registered. This vulnerability affects Firefox
    < 82. (CVE-2020-15680)

  - When multiple WASM threads had a reference to a module, and were looking up exported functions, one WASM
    thread could have overwritten another's entry in a shared stub table, resulting in a potentially
    exploitable crash. This vulnerability affects Firefox < 82. (CVE-2020-15681)

  - When a link to an external protocol was clicked, a prompt was presented that allowed the user to choose
    what application to open it in. An attacker could induce that prompt to be associated with an origin they
    didn't control, resulting in a spoofing attack. This was fixed by changing external protocol prompts to be
    tab-modal while also ensuring they could not be incorrectly associated with a different origin. This
    vulnerability affects Firefox < 82. (CVE-2020-15682)

The remote Ubuntu 16.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4599-2 advisory.

    USN-4599-1 fixed vulnerabilities in Firefox. This update provides the corresponding updates for Ubuntu     16.04 LTS.



Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 18.04 LTS / 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4599-1 advisory.

    Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially     crafted website, an attacker could potentially exploit these to cause a denial of service, spoof the     prompt for opening an external application, obtain sensitive information, or execute arbitrary code.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Firefox installed on the remote macOS or Mac OS X host is prior to 82.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-45 advisory.

  - Mozilla developers Christian Holler, Sebastian Hengst, Bogdan Tara, and Tyson Smith reported memory safety     bugs present in Firefox 81. 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. (CVE-2020-15684)

  - A use-after-free bug in the usersctp library was reported upstream. We assume this could have led to     memory corruption and a potentially exploitable crash. (CVE-2020-15969)

  - In the crossbeam rust crate, the bounded channel incorrectly assumed that Vec::fromiter had allocated     capacity that was the same as the number of iterator elements. Vec::fromiter does not actually guarantee     that and may allocate extra memory. The destructor of the bounded channel reconstructs Vec from the raw     pointer based on the incorrect assumptions - this is unsound and caused a deallocation with the incorrect     capacity when Vec::fromiter had allocated different sizes than the number of iterator elements. The impact     on Firefox is undetermined, but in another use case, the behavior was causing corruption of jemalloc     structures. (CVE-2020-15254)

  - If a valid external protocol handler was referenced in an image tag, the resulting broken image size could     be distinguished from a broken image size of a non-existent protocol handler. This allowed an attacker to     successfully probe whether an external protocol handler was registered. (CVE-2020-15680)

  - When multiple WASM threads had a reference to a module, and were looking up exported functions, one WASM     thread could have overwritten another's entry in a shared stub table, resulting in a potentially     exploitable crash. (CVE-2020-15681)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Firefox installed on the remote Windows host is prior to 82.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-45 advisory.

  - Mozilla developers Christian Holler, Sebastian Hengst, Bogdan Tara, and Tyson Smith reported memory safety     bugs present in Firefox 81. 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. (CVE-2020-15684)

  - A use-after-free bug in the usersctp library was reported upstream. We assume this could have led to     memory corruption and a potentially exploitable crash. (CVE-2020-15969)

  - In the crossbeam rust crate, the bounded channel incorrectly assumed that Vec::fromiter had allocated     capacity that was the same as the number of iterator elements. Vec::fromiter does not actually guarantee     that and may allocate extra memory. The destructor of the bounded channel reconstructs Vec from the raw     pointer based on the incorrect assumptions - this is unsound and caused a deallocation with the incorrect     capacity when Vec::fromiter had allocated different sizes than the number of iterator elements. The impact     on Firefox is undetermined, but in another use case, the behavior was causing corruption of jemalloc     structures. (CVE-2020-15254)

  - If a valid external protocol handler was referenced in an image tag, the resulting broken image size could     be distinguished from a broken image size of a non-existent protocol handler. This allowed an attacker to     successfully probe whether an external protocol handler was registered. (CVE-2020-15680)

  - When multiple WASM threads had a reference to a module, and were looking up exported functions, one WASM     thread could have overwritten another's entry in a shared stub table, resulting in a potentially     exploitable crash. (CVE-2020-15681)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
246765	Linux Distros Unpatched Vulnerability : CVE-2020-15254	Nessus	Misc.	critical
427195	Alpine: multiple librewolf packages: security update to 82.0-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	critical
427195	Alpine: multiple librewolf packages: security update to 82.0-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	critical
404373	Alpine: multiple firefox packages: security update to 82.0-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	critical
404373	Alpine: multiple firefox packages: security update to 82.0-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	critical
141923	Ubuntu 16.04 LTS : Firefox vulnerabilities (USN-4599-2)	Nessus	Ubuntu Local Security Checks	critical
141863	Ubuntu 18.04 LTS / 20.04 LTS : Firefox vulnerabilities (USN-4599-1)	Nessus	Ubuntu Local Security Checks	critical
141572	Mozilla Firefox < 82.0	Nessus	MacOS X Local Security Checks	critical
141571	Mozilla Firefox < 82.0	Nessus	Windows	critical

Detections

Analytics

CVE-2020-15254

critical

Tenable Plugins

critical

critical

critical

critical

critical

critical

critical

critical

critical