1. What is this vulnerability and why does it matter?

This vulnerability, identified as CVE-2022-28940, affects H3C MagicR100 routers. It allows unauthorized access to the /Ajax/ajaxget interface. Attackers can leverage this unauthorized access to send a large amount of data through the ajaxmsg parameter, which can lead to a Denial of Service (DoS) attack. This matters because a successful DoS attack can disrupt network services, rendering the affected device and potentially the network it supports, unavailable to legitimate users.

2. What are the CVSS score, severity level, and disclosure details?

The CVSS score for this vulnerability is 7.5, which indicates a High severity level. The vulnerability was published on May 4, 2022, at 15:40:06 UTC, and was last modified on August 3, 2024, at 06:10:57 UTC.

3. Which products, vendors, systems, and versions are affected?

• Vendor: H3C
• Product: MagicR100
• Affected Versions: All versions up to and including V100R005 (<=V100R005)

4. What is the technical root cause and attack vector?

The technical root cause of this vulnerability is an authorization bypass flaw in the H3C MagicR100 firmware. Specifically, the /Ajax/ajaxget interface can be accessed without proper authentication. The attack vector involves sending a large volume of data via the ajaxmsg parameter to this unauthenticated interface, which overwhelms the device's resources and leads to a Denial of Service condition.

5. How can this vulnerability be exploited?

This vulnerability can be exploited by an unauthenticated attacker. The attacker needs to send specially crafted HTTP requests to the vulnerable H3C MagicR100 device. By accessing the /Ajax/ajaxget interface and including a large amount of data within the ajaxmsg parameter, the attacker can cause the device to become unresponsive, effectively initiating a Denial of Service attack.

6. What mitigation steps and patches are available?

Specific mitigation steps or direct patch information are not detailed in the provided CVE data. Users of H3C MagicR100 devices are advised to contact H3C directly or consult their official support channels for information on firmware updates or security patches that address this vulnerability. Generally, updating to the latest firmware version released by the vendor is the primary recommendation.

7. How can vulnerable systems be detected?

Vulnerable systems can be detected by identifying the model and firmware version of H3C MagicR100 routers in use. Any H3C MagicR100 device running firmware version V100R005 or earlier (<=V100R005) is considered vulnerable to CVE-2022-28940. Network scanning tools can be used to identify H3C devices and potentially their firmware versions.

8. What are the indicators of compromise (IOCs)?

Indicators of Compromise for this vulnerability would primarily involve observations related to a Denial of Service attack. These may include:

• Sudden and unexplained unavailability or unresponsiveness of the H3C MagicR100 router.
• Unusually high network traffic directed towards the /Ajax/ajaxget endpoint of the router.
• Increased CPU or memory utilization on the router, leading to performance degradation.

9. Which threat actors are known to exploit this vulnerability?

While the provided information states that "Active exploits have been published to exploit the vulnerability," it does not specifically name any particular threat actors or groups known to be exploiting CVE-2022-28940 in the wild. The availability of public exploits increases the risk of exploitation by various opportunistic attackers.

10. What public intelligence references and advisories exist?

The primary public intelligence reference for this vulnerability is the CVE identifier itself: CVE-2022-28940. Further details and any official advisories would typically be found on the CVE Mitre database, vendor security bulletins from H3C, and potentially cybersecurity news outlets or vulnerability databases that track publicly disclosed flaws.

11. What is the risk assessment and urgency level?

The risk assessment for CVE-2022-28940 is High, as indicated by its CVSS score of 7.5. The urgency level is also High due to several factors:

• The vulnerability allows for unauthenticated Denial of Service attacks.
• Active exploits have been published, making it easier for a broader range of attackers to exploit.
• Successful exploitation can lead to significant operational disruption and service unavailability.

Organizations using affected H3C MagicR100 devices should prioritize investigation and apply any available patches or workarounds immediately to mitigate the risk.