External risk intelligence

Asseco SEE Live Component Vulnerability Allows Remote Attachment Execution

CVE advisorySeverity: CRITICAL (CVSS 9.9)

CVE-2025-66956

The vulnerability affects E-mail, SMS, and Fax communication components within a web-based platform. Such communication and messaging services are commonly deployed as internet-facing applications or gateways to handle external traffic, making them reachable and accessible from the public internet in standard deployment patterns.

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory highlights a critical vulnerability in Asseco SEE Live's communication components, specifically affecting how contact plans, emails, SMS, and faxes handle attachments. The issue could allow unauthorized remote access and execution of files through specially crafted URLs, potentially impacting the confidentiality and integrity of sensitive information. The main concern is confirming relevance and exposure given the nature of these communication channels.

Attackers can run unauthorized code via attachments.
Affects key communication channels; confirm relevance.
Understand exposure; investigate potential data compromise.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by tricking a user into clicking a specially crafted URL. This URL would allow them to bypass access controls and access or execute attachments within the application's Contact Plan, E-mail, SMS, and Fax features.

Entry Condition: User clicks a malicious link.
Trigger Point: Computable URL in E-mail/SMS/Fax.
Resulting Risk: Unauthorized access and execution.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow remote attackers to access and execute attachments within the Contact Plan, E-mail, SMS, and Fax components. This exposure is possible when a user clicks on a specially crafted, computable URL.

Sensitive information and system data.
Via a computable URL in email/SMS.
Unauthorized access and execution of attachments.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Contact Plan, E-Mail, SMS, and Fax components of Asseco SEE Live are impacted, suggesting that application owners and platform teams are likely responsible for remediation. The first practical step is to identify all instances of this technology, confirm their reachability and business criticality, and then assign ownership to the accountable party to plan a risk-based remediation strategy.

Application and platform teams own the issue.
Verify internet-facing instances and business criticality.
Plan remediation based on exposure and impact.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Asseco SEE Live?

Asseco SEE Live is a web-based software platform used for managing enterprise communications. It includes specific modules for handling contact plans, emails, SMS, and fax transmissions. Organizations use these components to automate and streamline messaging workflows, often integrating them into broader business processes to facilitate external outreach and document delivery.

What does Insecure Access Control mean for CVE-2025-66956?

This vulnerability falls under the weakness class of Improper Access Control (CWE-284). In plain terms, it means the application fails to properly verify if a user has permission to view or interact with specific files. Because of this flaw, the system does not correctly restrict access to attachments within its messaging components, allowing unauthorized users to interact with them.

How is this vulnerability triggered?

An attacker triggers this flaw by using a specially crafted, computable URL that targets attachments within the communication components. The vulnerability is specifically linked to these generated URLs; it is not triggered by simply having the software installed or active. Successful exploitation relies on the application processing these malicious links when they are accessed.

Is my system at risk?

Halo Surface Signal indicates that because Asseco SEE Live messaging components are typically used as gateways to process external traffic, they are often deployed in internet-facing configurations. This makes them reachable from the public internet. If your instance is accessible externally, the risk is higher. You should assess whether your specific deployment exposes these messaging interfaces to the public.

What should I do if I use Asseco SEE Live?

Your first step is to locate all deployments of the software within your environment and determine if they are exposed to the internet. Once mapped, verify the business criticality of those specific instances. Engage the relevant application or platform team to review access logs and prioritize remediation based on whether these communication channels are reachable by unauthorized parties.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.