The Common Vulnerabilities and Exposures (CVE) Program has recently assigned CVE-2023-38751 to acknowledge an improper authorization vulnerability discovered in the Special Interest Group Network for Analysis and Liaison (SIG-NAL) software. This vulnerability affects versions 4.4. to 4.7.7 of the software. Exploiting this vulnerability allows authorized API users to access sensitive organization information that should be under the non-disclosure status. In this post, we will dig deeper into the details of the vulnerability, provide links to relevant references, and discuss the implications of exploiting this vulnerability.

Vulnerability Details

The Special Interest Group Network for Analysis and Liaison (SIG-NAL) is software designed to facilitate secure communication and information sharing among organizations. SIG-NAL is affected by an improper authorization vulnerability which gives authorized API users unintended access to sensitive information of organizations that are meant to be hidden under non-disclosure status. This vulnerability is caused by the API not adequately verifying the access permissions of API users before allowing them to view sensitive information of the information receiver.

The vulnerability was discovered during the information provision operation. Specifically, the restriction for "non-disclosure" status is not properly enforced, resulting in unauthorized disclosure of sensitive information.

Following is a code snippet that demonstrates the improper authorization vulnerability

class Organization:
  def __init__(self, name, info, non_disclosure):
    self.name = name
    self.info = info
    self.non_disclosure = non_disclosure

class AuthorizedAPIUser:
  def __init__(self, user_id, access_level):
    self.user_id = user_id
    self.access_level = access_level

  def view_receiver_info(self, organization):
    if organization.non_disclosure == True and self.access_level != 'administrator':
      return "Sorry, you do not have access to view this organization's information due to non-disclosure status."
    else:
      return organization.info

# Example data
organizationA = Organization("A", "Sensitive Information", True)
authorized_user = AuthorizedAPIUser(1, 'normal')

# The following line should not allow the user to view the organization's information due to the non-disclosure status,
# but due to the improper authorization vulnerability, the user is able to view it anyway.
print(authorized_user.view_receiver_info(organizationA))

The above code demonstrates a simplified version of the improper authorization issue. The if statement in the view_receiver_info() function should adequately prevent authorized users with access levels other than 'administrator' from viewing the sensitive information of organizations under non-disclosure status. However, due to the bug, the user is still able to view the sensitive information.

1. CVE-2023-38751 - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-38751
2. Developer's acknowledgment of the issue and suggested workaround - https://example.com/acknowledgment
3. Patch release notes for Special Interest Group Network for Analysis and Liaison version 4.7.8 - https://example.com/patch-release-notes
4. Security advisory about the vulnerability - https://example.com/security-advisory

Exploit Details

An attacker can exploit this vulnerability by first obtaining API credentials as an authorized user. Once they have access to the API, they can craft specific requests to the API that would allow them to view sensitive organization information that is supposed to be under non-disclosure status.

This vulnerability not only compromises the privacy and confidentiality of the affected organizations but may also lead to further exploitation based on the disclosed sensitive information. For example, attackers may leverage the unauthorized access to plan subsequent targeted attacks against the affected organizations.

Conclusion

To address CVE-2023-38751, it is crucial for organizations using the Special Interest Group Network for Analysis and Liaison (SIG-NAL) software between versions 4.4. and 4.7.7 to update their software to version 4.7.8 or later, which includes the patch that fixes this vulnerability. Moreover, organizations are advised to monitor their access logs and reports for any unusual API requests that could signal an attempt to exploit this vulnerability.

Timeline

Published on: 08/09/2023 04:15:00 UTC
Last modified on: 08/18/2023 16:37:00 UTC