An information leak vulnerability was discovered in HAProxy 2.1, 2.2 before 2.2.27, 2.3, 2.4 before 2.4.21, 2.5 before 2.5.11, 2.6 before 2.6.8, 2.7 before 2.7.1. There are 5 bytes left uninitialized in the connection buffer when encoding the FCGI_BEGIN_REQUEST record. Sensitive data may be disclosed to configured FastCGI backends in an unexpected way.

An update of the haproxy package has been released.

The remote CentOS Linux 9 host has a package installed that is affected by a vulnerability as referenced in the haproxy-2.4.22-1.el9 build changelog.

  - An information leak vulnerability was discovered in HAProxy 2.1, 2.2 before 2.2.27, 2.3, 2.4 before     2.4.21, 2.5 before 2.5.11, 2.6 before 2.6.8, 2.7 before 2.7.1. There are 5 bytes left uninitialized in the     connection buffer when encoding the FCGI_BEGIN_REQUEST record. Sensitive data may be disclosed to     configured FastCGI backends in an unexpected way. (CVE-2023-0836)

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

According to the versions of the haproxy package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - An information leak vulnerability was discovered in HAProxy 2.1, 2.2 before 2.2.27, 2.3, 2.4 before     2.4.21, 2.5 before 2.5.11, 2.6 before 2.6.8, 2.7 before 2.7.1. There are 5 bytes left uninitialized in the     connection buffer when encoding the FCGI_BEGIN_REQUEST record. Sensitive data may be disclosed to     configured FastCGI backends in an unexpected way. (CVE-2023-0836)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote Oracle Linux 9 host has a package installed that is affected by a vulnerability as referenced in the ELSA-2023-6496 advisory.

    [2.4.22-1]
    - Update to 2.4.22 (#2196530)

    [2.4.17-7]
    - Fix uninitizalized resevered bytes (CVE-2023-0836, #2180861)

Tenable has extracted the preceding description block directly from the Oracle 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 remote Redhat Enterprise Linux 9 host has a package installed that is affected by a vulnerability as referenced in the RHSA-2023:6496 advisory.

  - haproxy: data leak via fcgi requests (CVE-2023-0836)

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

The version of haproxy2 installed on the remote host is prior to 2.2.17-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2HAPROXY2-2023-002 advisory.

  - An out-of-bounds read in dns_validate_dns_response in dns.c was discovered in HAProxy through 1.8.14. Due     to a missing check when validating DNS responses, remote attackers might be able read the 16 bytes     corresponding to an AAAA record from the non-initialized part of the buffer, possibly accessing anything     that was left on the stack, or even past the end of the 8193-byte buffer, depending on the value of     accepted_payload_size. (CVE-2018-20102)

  - An information leak vulnerability was discovered in HAProxy 2.1, 2.2 before 2.2.27, 2.3, 2.4 before     2.4.21, 2.5 before 2.5.11, 2.6 before 2.6.8, 2.7 before 2.7.1. There are 5 bytes left uninitialized in the     connection buffer when encoding the FCGI_BEGIN_REQUEST record. Sensitive data may be disclosed to     configured FastCGI backends in an unexpected way. (CVE-2023-0836)

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 host has packages installed that are affected by a vulnerability as referenced in the dsa-5388 advisory.

  - An information leak vulnerability was discovered in HAProxy 2.1, 2.2 before 2.2.27, 2.3, 2.4 before     2.4.21, 2.5 before 2.5.11, 2.6 before 2.6.8, 2.7 before 2.7.1. There are 5 bytes left uninitialized in the     connection buffer when encoding the FCGI_BEGIN_REQUEST record. Sensitive data may be disclosed to     configured FastCGI backends in an unexpected way. (CVE-2023-0836)

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

The remote Ubuntu 22.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-5994-1 advisory.

    It was discovered that HAProxy incorrectly initialized certain connection buffers. A remote attacker could     possibly use this issue to obtain 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	Severity
203435	Photon OS 4.0: Haproxy PHSA-2023-4.0-0373	Nessus	PhotonOS Local Security Checks	high
191148	CentOS 9 : haproxy-2.4.22-1.el9	Nessus	CentOS Local Security Checks	high
188205	EulerOS 2.0 SP11 : haproxy (EulerOS-SA-2023-2645)	Nessus	Huawei Local Security Checks	high
188200	EulerOS 2.0 SP11 : haproxy (EulerOS-SA-2023-2687)	Nessus	Huawei Local Security Checks	high
185844	Oracle Linux 9 : haproxy (ELSA-2023-6496)	Nessus	Oracle Linux Local Security Checks	high
185156	RHEL 9 : haproxy (RHSA-2023:6496)	Nessus	Red Hat Local Security Checks	high
182016	Amazon Linux 2 : haproxy2 (ALASHAPROXY2-2023-002)	Nessus	Amazon Linux Local Security Checks	high
174275	Debian DSA-5388-1 : haproxy - security update	Nessus	Debian Local Security Checks	high
173797	Ubuntu 22.04 LTS : HAProxy vulnerability (USN-5994-1)	Nessus	Ubuntu Local Security Checks	high

Detections

Analytics

CVE-2023-0836

high

Tenable Plugins

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