A flaw was found in the xdg-email component of xdg-utils-1.1.0-rc1 and newer. When handling mailto: URIs, xdg-email allows attachments to be discreetly added via the URI when being passed to Thunderbird. An attacker could potentially send a victim a URI that automatically attaches a sensitive file to a new email. If a victim user does not notice that an attachment was added and sends the email, this could result in sensitive information disclosure. It has been confirmed that the code behind this issue is in xdg-email and not in Thunderbird.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - A flaw was found in the xdg-email component of xdg-utils-1.1.0-rc1 and newer. When handling mailto: URIs,
    xdg-email allows attachments to be discreetly added via the URI when being passed to Thunderbird. An
    attacker could potentially send a victim a URI that automatically attaches a sensitive file to a new
    email. If a victim user does not notice that an attachment was added and sends the email, this could
    result in sensitive information disclosure. It has been confirmed that the code behind this issue is in
    xdg-email and not in Thunderbird. (CVE-2020-27748)

The AlmaLinux 9.2 host has a package installed that is affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.2:CLSA-2025:1751913634 advisory.

  - A flaw was found in the xdg-email component of xdg-utils-1.1.0-rc1 and newer. When handling mailto: URIs,     xdg-email allows attachments to be discreetly added via the URI when being passed to Thunderbird. An     attacker could potentially send a victim a URI that automatically attaches a sensitive file to a new     email. If a victim user does not notice that an attachment was added and sends the email, this could     result in sensitive information disclosure. It has been confirmed that the code behind this issue is in     xdg-email and not in Thunderbird. (CVE-2020-27748)

  - When xdg-mail is configured to use thunderbird for mailto URLs, improper parsing of the URL can lead to     additional headers being passed to thunderbird that should not be included per RFC 2368. An attacker can     use this method to create a mailto URL that looks safe to users, but will actually attach files when     clicked. (CVE-2022-4055)

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

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2025-002294 advisory.

    A flaw was found in the xdg-email component of xdg-utils-1.1.0-rc1 and newer. When handling mailto: URIs,     xdg-email allows attachments to be discreetly added via the URI when being passed to Thunderbird. An     attacker could potentially send a victim a URI that automatically attaches a sensitive file to a new     email. If a victim user does not notice that an attachment was added and sends the email, this could     result in sensitive information disclosure. It has been confirmed that the code behind this issue is in     xdg-email and not in Thunderbird.

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

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

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

  - A flaw was found in the xdg-email component of xdg-utils-1.1.0-rc1 and newer. When handling mailto: URIs,     xdg-email allows attachments to be discreetly added via the URI when being passed to Thunderbird. An     attacker could potentially send a victim a URI that automatically attaches a sensitive file to a new     email. If a victim user does not notice that an attachment was added and sends the email, this could     result in sensitive information disclosure. It has been confirmed that the code behind this issue is in     xdg-email and not in Thunderbird. (CVE-2020-27748)

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

The version of xdg-utils installed on the remote host is prior to 1.1.0-0.17.20120809git. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2023-2002 advisory.

    A flaw was found in the xdg-email component of xdg-utils-1.1.0-rc1 and newer. When handling mailto: URIs,     xdg-email allows attachments to be discreetly added via the URI when being passed to Thunderbird. An     attacker could potentially send a victim a URI that automatically attaches a sensitive file to a new     email. If a victim user does not notice that an attachment was added and sends the email, this could     result in sensitive information disclosure. It has been confirmed that the code behind this issue is in     xdg-email and not in Thunderbird. (CVE-2020-27748)

    When xdg-mail is configured to use thunderbird for mailto URLs, improper parsing of the URL can lead to     additional headers being passed to thunderbird that should not be included per RFC 2368. An attacker can     use this method to create a mailto URL that looks safe to users, but will actually attach files when     clicked. (CVE-2022-4055)

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

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

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2023-007 advisory.

    A flaw was found in the xdg-email component of xdg-utils-1.1.0-rc1 and newer. When handling mailto: URIs,     xdg-email allows attachments to be discreetly added via the URI when being passed to Thunderbird. An     attacker could potentially send a victim a URI that automatically attaches a sensitive file to a new     email. If a victim user does not notice that an attachment was added and sends the email, this could     result in sensitive information disclosure. It has been confirmed that the code behind this issue is in     xdg-email and not in Thunderbird. (CVE-2020-27748)

    When xdg-mail is configured to use thunderbird for mailto URLs, improper parsing of the URL can lead to     additional headers being passed to thunderbird that should not be included per RFC 2368. An attacker can     use this method to create a mailto URL that looks safe to users, but will actually attach files when     clicked. (CVE-2022-4055)

Tenable has extracted the preceding description block directly from the tested product 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 16.04 LTS / 18.04 LTS / 20.04 LTS host has a package installed that is affected by a vulnerability as referenced in the USN-4649-1 advisory.

    Jens Mueller discovered that xdg-utils incorrectly handled certain URI. An attacker could possibly use     this issue to expose sensitive information.

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

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

ID	Name	Product	Family	Type	Severity
459294	Echo: xdg-utils: security update to 1.2.1-2+e1	Tenable Cloud Security	Echo Local Security Checks	Local	medium
459294	Echo: xdg-utils: security update to 1.2.1-2+e1	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
351805	AlmaLinux 9.2 [TuxCare] Security Update: xdg-utils Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2025:1751913634)	Nessus	Alma Linux Local Security Checks	Local	high
341233	Unity Linux 20.1050e / 20.1060e / 20.1070-8ae / 20.1070e Security Update: xdg-utils (UTSA-2025-002294)	Nessus	Unity Linux Local Security Checks	Local	medium
223567	Linux Distros Unpatched Vulnerability : CVE-2020-27748	Nessus	Misc.	Local	medium
173234	Amazon Linux 2 : xdg-utils (ALAS-2023-2002)	Nessus	Amazon Linux Local Security Checks	Local	high
173127	Amazon Linux 2023 : xdg-utils (ALAS2023-2023-007)	Nessus	Amazon Linux Local Security Checks	Local	high
143268	Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : xdg-utils vulnerability (USN-4649-1)	Nessus	Ubuntu Local Security Checks	Local	medium

Detections

Analytics

CVE-2020-27748

medium

Tenable Plugins

medium

medium

high

medium

medium

high

high

medium