Memory safety bugs present in Firefox 133 and Thunderbird 133. 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 < 134 and Thunderbird < 134.

The version of Thunderbird installed on the remote Windows host is prior to 134.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2025-04 advisory.

  - Memory safety bugs present in Firefox 133 and Thunderbird 133. 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-2025-0247)

  - Memory safety bugs present in Firefox 133, Thunderbird 133, Firefox ESR 115.18, Firefox ESR 128.5,     Thunderbird 115.18, and Thunderbird 128.5. 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-2025-0242)

  - The Matrix specification demands homeservers to perform validation of the server-name and media-id     components of MXC URIs with the intent to prevent path traversal. However, it is not mentioned that a     similar check must also be performed on the client to prevent client-side path traversal. matrix-js-sdk     fails to perform this validation. (CVE-2024-50336)

  - The WebChannel API, which is used to transport various information across processes, did not check the     sending principal but rather accepted the principal being sent. This could have led to privilege     escalation attacks. (CVE-2025-0237)

  - Assuming a controlled failed memory allocation, an attacker could have caused a use-after-free, leading to     a potentially exploitable crash. (CVE-2025-0238)

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 Thunderbird installed on the remote macOS or Mac OS X host is prior to 134.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2025-04 advisory.

  - Memory safety bugs present in Firefox 133 and Thunderbird 133. 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-2025-0247)

  - Memory safety bugs present in Firefox 133, Thunderbird 133, Firefox ESR 115.18, Firefox ESR 128.5,     Thunderbird 115.18, and Thunderbird 128.5. 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-2025-0242)

  - The Matrix specification demands homeservers to perform validation of the server-name and media-id     components of MXC URIs with the intent to prevent path traversal. However, it is not mentioned that a     similar check must also be performed on the client to prevent client-side path traversal. matrix-js-sdk     fails to perform this validation. (CVE-2024-50336)

  - The WebChannel API, which is used to transport various information across processes, did not check the     sending principal but rather accepted the principal being sent. This could have led to privilege     escalation attacks. (CVE-2025-0237)

  - Assuming a controlled failed memory allocation, an attacker could have caused a use-after-free, leading to     a potentially exploitable crash. (CVE-2025-0238)

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

The remote Fedora 40 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2025-e8a71b6caf advisory.

    - Updated to latest upstream (134.0)

Tenable has extracted the preceding description block directly from the Fedora 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 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-7191-1 advisory.

    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-2025-0237, CVE-2025-0239,     CVE-2025-0240, CVE-2025-0242, CVE-2025-0243, CVE-2025-0247)

    Irvan Kurniawan discovered that Firefox incorrectly handled memory when breaking lines in text, leading to     a use-after-free vulnerability. An attacker could possibly use this issue to cause a denial of service or     possibly execute arbitrary code. (CVE-2025-0238)

    Nils Bars discovered that Firefox incorrectly handled memory when using JavaScript Text Segmentation. An     attacker could possibly use this issue to cause a denial of service. (CVE-2025-0241)

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 Fedora 41 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2025-6fcde64d77 advisory.

    - Updated to latest upstream (134.0)

Tenable has extracted the preceding description block directly from the Fedora 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 Windows host is prior to 134.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2025-01 advisory.

  - Memory safety bugs present in Firefox 133, Thunderbird 133, Firefox ESR 115.18, Firefox ESR 128.5,     Thunderbird 115.18, and Thunderbird 128.5. 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-2025-0242)

  - When redirecting to an invalid protocol scheme, an attacker could spoof the address bar.  Note: This issue     only affected Android operating systems. Other operating systems are unaffected. (CVE-2025-0244)

  - Under certain circumstances, a user opt-in setting that Focus should require authentication before use     could have been be bypassed. (CVE-2025-0245)

  - When using an invalid protocol scheme, an attacker could spoof the address bar.  Note: This issue only     affected Android operating systems. Other operating systems are unaffected. Note: This issue is a     different issue from CVE-2025-0244. (CVE-2025-0246)

  - The WebChannel API, which is used to transport various information across processes, did not check the     sending principal but rather accepted the principal being sent. This could have led to privilege     escalation attacks. (CVE-2025-0237)

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 134.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2025-01 advisory.

  - Memory safety bugs present in Firefox 133, Thunderbird 133, Firefox ESR 115.18, Firefox ESR 128.5,     Thunderbird 115.18, and Thunderbird 128.5. 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-2025-0242)

  - When redirecting to an invalid protocol scheme, an attacker could spoof the address bar.  Note: This issue     only affected Android operating systems. Other operating systems are unaffected. (CVE-2025-0244)

  - Under certain circumstances, a user opt-in setting that Focus should require authentication before use     could have been be bypassed. (CVE-2025-0245)

  - When using an invalid protocol scheme, an attacker could spoof the address bar.  Note: This issue only     affected Android operating systems. Other operating systems are unaffected. Note: This issue is a     different issue from CVE-2025-0244. (CVE-2025-0246)

  - The WebChannel API, which is used to transport various information across processes, did not check the     sending principal but rather accepted the principal being sent. This could have led to privilege     escalation attacks. (CVE-2025-0237)

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
213633	Mozilla Thunderbird < 134.0	Nessus	Windows	medium
213632	Mozilla Thunderbird < 134.0	Nessus	MacOS X Local Security Checks	medium
213613	Fedora 40 : firefox (2025-e8a71b6caf)	Nessus	Fedora Local Security Checks	high
213603	Ubuntu 20.04 LTS : Firefox vulnerabilities (USN-7191-1)	Nessus	Ubuntu Local Security Checks	high
213553	Fedora 41 : firefox (2025-6fcde64d77)	Nessus	Fedora Local Security Checks	high
213528	Mozilla Firefox < 134.0	Nessus	Windows	high
213527	Mozilla Firefox < 134.0	Nessus	MacOS X Local Security Checks	high

Detections

Analytics

CVE-2025-0247

critical

Tenable Plugins

medium

medium

high

high

high

high

high