How do you patch or mitigate CVE-2024-11680 (ProjectSend Improper Authentication)?

What makes CVE-2024-11680 a patch-or-mitigate-now issue?

The practical issue is not just that ProjectSend is vulnerable, but that CISA has already treated this flaw as something defenders should act on immediately. For a weakness that is being used in the wild, the operational question is whether you can remove the exposure fast enough, or whether the product must be taken out of service until vendor mitigation is available.

Start by finding every ProjectSend deployment, including forgotten test instances, externally reachable hosts and internally reachable systems that could still be reached from user networks or partner connections. The remediation decision is then simple: apply the vendor security update or documented mitigation, and if no supported fix exists, reduce exposure or discontinue use.

Because the flaw is an improper authentication problem, do not treat it as a cosmetic hardening issue. Any instance that still accepts unauthenticated or weakly authenticated access remains a candidate for account takeover, data access or further abuse until the vendor's instructions are in place and verified.

How should you validate that the fix actually reduced exposure?

Validation should focus on the service itself, not only on whether a package was installed. Confirm the affected ProjectSend instance is on the expected version or configuration state, verify that the access path has changed as intended, and check whether the application is still reachable from untrusted networks when it should not be.

If you cannot patch immediately, document the compensating control you actually rely on. In practice that means restricting network reachability, removing public exposure, or disabling the service until a supported remediation exists. A mitigation that depends on "nobody will find it" is not a mitigation.

After remediation, review the surrounding dependencies too, especially any reverse proxy, shared authentication layer, backup copy or administrative interface that could preserve the same exposure even after the application itself is fixed. That is where many partial remediations fail in real environments.

What should you check for after patching or mitigation?

Once the exposure is addressed, review logs and surrounding telemetry for signs of earlier exploitation. For exploited authentication flaws, useful indicators include unexpected logins, account creation or changes, unusual file access, suspicious administrative actions, and requests that do not fit normal user behaviour. If the product was internet-exposed, treat post-fix hunting as part of the remediation, not as an optional extra.

If you find evidence of compromise, prioritize credential and session review for any accounts that the application could have exposed or let attackers impersonate. That can include application administrator accounts, shared service credentials, API tokens, or linked integration accounts, depending on how the deployment was configured.

Use the response to confirm whether the asset belongs in the environment at all. When a product cannot be safely patched, the correct outcome may be retirement, replacement, or isolation rather than repeated exception handling.

Risk and Threat Considerations

An improper authentication flaw is attractive because it can turn a normal application into a direct access path. When the product is exposed to the internet, even brief delay in patching can leave a window for account abuse, unauthorized file access, or follow-on movement into connected systems.

Failure mechanism: Attackers exploit weak or broken authentication handling to reach application functions without the intended proof of identity, then use that foothold to access data or operate as a trusted user.

Impact: The likely outcomes are unauthorized access, data exposure, account compromise, and the need for incident response if logs or behaviour show that the flaw was already abused before remediation.

Practitioner Guidance

What to prioritise: Inventory first, then exposure reduction, then verification. The fastest risk reduction usually comes from identifying every live ProjectSend instance and removing public reachability before you debate whether patching can happen in the next maintenance window.

What to verify: Confirm the remediation path is actually vendor-supported for your deployment, and verify that no alternate route still exposes the service. If the application is kept alive through an exception, the exception itself becomes the control point and should be reviewed with the same rigor as the patch.

Decision rule: If you cannot apply the vendor fix or supported mitigation quickly, take the service out of service rather than leaving a known exploitable authentication weakness online. For an exploited flaw, continued exposure is the higher-risk choice.

Practitioner takeaway: For this CVE, speed matters less than certainty, you need a verified fix or a verified removal of exposure, plus a compromise check immediately after the change.

Related resources from NHI Mgmt Group

• Guide: Zero-Day and Exploited Vulnerabilities Guide
• How do you patch or mitigate CVE-2024-0012 (Palo Alto Networks PAN-OS Management Interface Authentication Bypass)?
• How do you patch or mitigate CVE-2024-5910 (Palo Alto Networks Expedition Missing Authentication)?
• How do you patch or mitigate CVE-2020-12812 (Fortinet FortiOS SSL VPN Improper Authentication)?
• How do you patch or mitigate CVE-2021-27877 (Veritas Backup Exec Agent Improper Authentication)?