CVE-2026-77067 in Omnivore
Summary
by MITRE • 08/20/2026
The setWebhookResolver in packages/api/src/resolvers/webhooks/index.ts stores the caller-supplied url without any address validation, and the file imports no validation helper. When a subscribed event fires, callWebhook in packages/api/src/jobs/call_webhook.ts issues axios.request with that url, the method and Content-Type recorded on the webhook, and a JSON body carrying the event data, so an authenticated user can make the server send repeated attacker-shaped requests to internal endpoints, including link-local metadata addresses. The request is blind: callWebhook discards the result and writes only a success line or the axios error to the server log, so the response is not returned through the API.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified in this scenario constitutes an Unrestricted URL Redirection leading to Server-Side Request Forgery (SSRF), specifically affecting internal network resources due to insufficient input validation on webhook configuration endpoints. The core technical flaw resides within the setWebhookResolver function located in packages/api/src/resolvers/webhooks/index.ts, which accepts a caller-supplied Uniform Resource Locator and persists it directly into storage without performing any address sanitization or domain verification checks. This lack of validation is compounded by the absence of imported security helper modules that would typically enforce strict allowlists for permitted protocols such as HTTP or HTTPS while explicitly blocking dangerous schemes like file, gopher, or dict. By storing this unvalidated URL, the application creates a persistent vector for exploitation where any authenticated user can configure the system to act as an unauthorized proxy on behalf of the server infrastructure.
When a subscribed event triggers within the application lifecycle, the callWebhook function in packages/api/src/jobs/call_webhook.ts initiates an outbound HTTP request using the axios library. This request utilizes the method and Content-Type headers recorded during webhook creation, along with a JSON payload containing sensitive event data. Because the target URL was not validated upon ingestion, attackers can manipulate this field to point towards internal network endpoints that are otherwise inaccessible from external networks or restricted by firewall rules. A critical aspect of this vulnerability is its ability to reach link-local metadata addresses, such as those found at 169.254.169.254 in cloud environments like AWS EC2 or Azure Managed Identity services. By directing requests to these internal endpoints, an attacker can potentially retrieve instance identity documents, access tokens, and other credentials that are crucial for further lateral movement within the compromised environment.
The operational impact of this vulnerability is significant due to its blind nature. The callWebhook function discards the HTTP response body entirely, logging only a success message or an axios error object if the request fails. This design choice means that standard SSRF techniques relying on reading server responses are not directly applicable through the API interface itself. However, the impact remains severe because the attacker can still cause denial of service by flooding internal services with repeated requests, potentially exhausting resources or triggering rate limits on critical infrastructure components. Furthermore, even without response exfiltration via the primary channel, blind SSRF attacks can be leveraged for out-of-band data extraction using techniques such as DNS logging servers or HTTP callback endpoints controlled by the attacker. This allows the retrieval of sensitive information indirectly through side channels, bypassing the lack of direct response visibility in the application logs.
From a classification perspective, this vulnerability aligns with CWE-918 Server-Side Request Forgery and specifically falls under CWE-601 URL Redirection to Untrusted Site if considered broadly, but more accurately maps to SSRF affecting internal resources which is often associated with CWE-20 Improper Input Validation. In the context of the MITRE ATT&CK framework, this behavior corresponds to T1571 Non-Standard Port and potentially T1098 Authorized Impersonation or T1534 Internal Spearphishing depending on how the internal requests are utilized for lateral movement. The exploitation path involves an authenticated user abusing their privileges to configure malicious webhooks, which then triggers server-side actions that interact with restricted network segments.
Mitigation strategies must focus on implementing strict input validation at the point of ingestion within setWebhookResolver. This includes enforcing a whitelist approach where only specific domains or IP ranges are permitted for webhook targets, explicitly blocking private IP address ranges such as 10.x.x.x, 172.16.x.x through 172.31.x.x, and 192.168.x.x, along with link-local addresses like 169.254.x.x and loopback interfaces. Additionally, the application should reject non-HTTP or HTTPS protocols to prevent exploitation of other services via schemes like file or gopher. It is also advisable to implement network-level controls such as egress filtering on the server hosting the API to restrict outbound connections to only those destinations that are strictly required for business operations. Finally, modifying callWebhook to handle responses more securely and logging detailed context without exposing sensitive data can aid in detection and forensic analysis if an attack attempt occurs.