Exim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exim. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of NTLM challenge requests. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of the service account. . Was ZDI-CAN-17515.

The remote Fedora 40 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-0abcfebecd advisory.

    Automatic update for exim-4.96.1-1.fc40.

    ##### **Changelog**

    ```
    * Mon Oct  2 2023 Jaroslav karvada <jskarvad@redhat.com> - 4.96.1-1
    - New version       Resolves: rhbz#2241735       Resolves: rhbz#2241538       Resolves: rhbz#2241539       Resolves: rhbz#2241525       Resolves: rhbz#2241527       Resolves: rhbz#2241528       Resolves: rhbz#2241529       Resolves: rhbz#2241531       Resolves: rhbz#2241532       Resolves: rhbz#2241542       Resolves: rhbz#2241544

    ```

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 host is affected by the vulnerability described in GLSA-202402-18 (Exim: Multiple Vulnerabilities)

  - Exim before 4.97.1 allows SMTP smuggling in certain PIPELINING/CHUNKING configurations. Remote attackers     can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address,     allowing bypass of an SPF protection mechanism. This occurs because Exim supports <LF>.<CR><LF> but some     other popular e-mail servers do not. (CVE-2023-51766)

  - NTLM Challenge Out-Of-Bounds Read Information Disclosure Vulnerability [epel-all] (CVE-2023-42114)

  - AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability [epel-all] (CVE-2023-42115)

  - Exim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability (CVE-2023-42116,     CVE-2023-42117)

  - dnsdb Out-Of-Bounds Read Information Disclosure Vulnerability [epel-all] (CVE-2023-42119)

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

The remote openSUSE 15 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2024:0007-1 advisory.

  - A vulnerability was found in Exim and classified as problematic. This issue affects some unknown     processing of the component Regex Handler. The manipulation leads to use after free. The name of the patch     is 4e9ed49f8f12eb331b29bd5b6dc3693c520fddc2. It is recommended to apply a patch to fix this issue. The     identifier VDB-211073 was assigned to this vulnerability. (CVE-2022-3559)

  - NTLM Challenge Out-Of-Bounds Read Information Disclosure Vulnerability [epel-all] (CVE-2023-42114)

  - AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability [epel-all] (CVE-2023-42115)

  - Exim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability (CVE-2023-42116,     CVE-2023-42117)

  - dnsdb Out-Of-Bounds Read Information Disclosure Vulnerability [epel-all] (CVE-2023-42119)

  - Exim before 4.97.1 allows SMTP smuggling in certain PIPELINING/CHUNKING configurations. Remote attackers     can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address,     allowing bypass of an SPF protection mechanism. This occurs because Exim supports <LF>.<CR><LF> but some     other popular e-mail servers do not. (CVE-2023-51766)

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 39 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-f1c8e4c1cc advisory.

    This is new version of exim.

    ----

    This is an exim update fixing several security problems.

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 exim installed on the remote host is prior to 4.92-1.39. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS-2023-1860 advisory.

    Exim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability

    NOTE: https://www.zerodayinitiative.com/advisories/ZDI-23-1470/ (CVE-2023-42116)

    Exim Improper Neutralization of Special Elements Remote Code Execution Vulnerability

    NOTE: https://www.zerodayinitiative.com/advisories/ZDI-23-1471/ (CVE-2023-42117)

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.

According to its banner, the version of Exim running on the remote host is prior to 4.96.1. It is, therefore, potentially affected by multiple vulnerabilities:

    - NTLM Challenge Out-Of-Bounds Read (CVE-2023-42114)

    - AUTH Out-Of-Bounds Write (CVE-2023-42115)

    - SMTP Challenge Stack-based Buffer Overflow CVE-2023-42116)

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 37 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-0a7690525f advisory.

    This is an exim update fixing several security problems.

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 Fedora 38 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-42313af0de advisory.

    This is exim update fixing several security problems.

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 openSUSE 15 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2023:0293-1 advisory.

  - NTLM Challenge Out-Of-Bounds Read Information Disclosure Vulnerability [fedora-all] (CVE-2023-42114)

  - AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability [fedora-all] (CVE-2023-42115)

  - SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability [fedora-all]     (CVE-2023-42116)

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 ESM / 18.04 ESM / 20.04 LTS / 22.04 LTS / 23.04 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-6411-1 advisory.

    It was discovered that Exim incorrectly handled certain challenge requests. A remote attacker could     possibly use this issue to perform out-of-bounds reads, resulting in information leakage. (CVE-2023-42114)

    It was discovered that Exim incorrectly handled validation of user-supplied data. A remote attacker could     possibly use this issue to perform out-of-bounds writes, resulting in arbitrary code execution. This issue     only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 23.04. (CVE-2023-42115)

    It was discovered that Exim incorrectly handled certain challenge requests. A remote attacker could     possibly use this issue to perform out-of-bounds writes, resulting in arbitrary code execution.
    (CVE-2023-42116)

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 Debian 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-3599 advisory.

  - NTLM Challenge Out-Of-Bounds Read Information Disclosure Vulnerability [fedora-all] (CVE-2023-42114)

  - SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability [fedora-all]     (CVE-2023-42116)

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

The remote Debian 11 / 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-5512 advisory.

  - NTLM Challenge Out-Of-Bounds Read Information Disclosure Vulnerability [fedora-all] (CVE-2023-42114)

  - AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability [fedora-all] (CVE-2023-42115)

  - SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability [fedora-all]     (CVE-2023-42116)

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
194566	Fedora 40 : exim (2023-0abcfebecd)	Nessus	Fedora Local Security Checks	critical
190665	GLSA-202402-18 : Exim: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	medium
187650	openSUSE 15 Security Update : exim (openSUSE-SU-2024:0007-1)	Nessus	SuSE Local Security Checks	medium
185341	Fedora 39 : exim (2023-f1c8e4c1cc)	Nessus	Fedora Local Security Checks	critical
183852	Amazon Linux AMI : exim (ALAS-2023-1860)	Nessus	Amazon Linux Local Security Checks	high
183509	Exim < 4.96.1 Multiple Vulnerabilities	Nessus	SMTP problems	critical
182768	Fedora 37 : exim (2023-0a7690525f)	Nessus	Fedora Local Security Checks	critical
182767	Fedora 38 : exim (2023-42313af0de)	Nessus	Fedora Local Security Checks	critical
182677	openSUSE 15 Security Update : exim (openSUSE-SU-2023:0293-1)	Nessus	SuSE Local Security Checks	critical
182528	Ubuntu 16.04 ESM / 18.04 ESM / 20.04 LTS / 22.04 LTS / 23.04 : Exim vulnerabilities (USN-6411-1)	Nessus	Ubuntu Local Security Checks	critical
182430	Debian DLA-3599-1 : exim4 - LTS security update	Nessus	Debian Local Security Checks	high
182426	Debian DSA-5512-1 : exim4 - security update	Nessus	Debian Local Security Checks	critical

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CVE-2023-42116

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