Fortinet FortiProxy curl and libcurl Multiple Vulnerabilities (FG-IR-23-385)

critical Nessus Plugin ID 192237

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Synopsis

The version of FortiProxy installed on the remote host is missing one or more security-related updates.

Description

The version of FortiProxy installed on the remote host is 7.0.x, 7.2.x prior to 7.2.8, or 7.4.x prior to 7.4.2. It is, therefore, affected by multiple vulnerabilities as referenced in the FG-IR-23-385 advisory.

- This flaw makes curl overflow a heap based buffer in the SOCKS5 proxy handshake. When curl is asked to pass along the host name to the SOCKS5 proxy to allow that to resolve the address instead of it getting done by curl itself, the maximum length that host name can be is 255 bytes. If the host name is detected to be longer, curl switches to local name resolving and instead passes on the resolved address only. Due to this bug, the local variable that means 'let the host resolve the name' could get the wrong value during a slow SOCKS5 handshake, and contrary to the intention, copy the too long host name to the target buffer instead of copying just the resolved address there. The target buffer being a heap based buffer, and the host name coming from the URL that curl has been told to operate with. (CVE-2023-38545)

- This flaw allows an attacker to insert cookies at will into a running program using libcurl, if the specific series of conditions are met. libcurl performs transfers. In its API, an application creates 'easy handles' that are the individual handles for single transfers. libcurl provides a function call that duplicates en easy handle called 'curl_easy_duphandle'. If a transfer has cookies enabled when the handle is duplicated, the cookie-enable state is also cloned - but without cloning the actual cookies. If the source handle did not read any cookies from a specific file on disk, the cloned version of the handle would instead store the file name as `none` (using the four ASCII letters, no quotes). Subsequent use of the cloned handle that does not explicitly set a source to load cookies from would then inadvertently load cookies from a file named `none` - if such a file exists and is readable in the current directory of the program using libcurl. And if using the correct file format of course. (CVE-2023-38546)

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

Solution

Please upgrade to FortiProxy version 7.2.8, 7.4.2 or later.

Plugin Details

Severity: Critical

ID: 192237

File Name: fortiproxy_FG-IR-23-385.nasl

Version: 1.2

Type: local

Family: Firewalls

Published: 3/19/2024

Updated: 3/20/2024

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2023-38545

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:fortinet:fortiproxy

Required KB Items: Host/Fortigate/model, Host/FortiProxy/version

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 12/8/2023

Vulnerability Publication Date: 11/14/2023

Reference Information

CVE: CVE-2023-38545, CVE-2023-38546

Detections

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