What is CVE-2020-3580?
The CVE-2020-3580 is a security vulnerability that was found within the Cisco Adaptive Security Appliance Software and Cisco Firepower Threat Defense Software. It gives an attacker the ability to perform a reflected cross-site scripting XSS attack due to improper input sanitization in the interface of the web services. It may impact several versions of Cisco ASA and FTD, which allows attackers to inject and then execute malicious scripts within the context of the affected web interface.
CVSS Score and Severity
- CVSS Score: 6.1 (Medium)
- Severity: Medium severity due to the score of 6.1 out of 10 according to the CVSS system. This is a considerable threat because XSS-type attacks may exploit the web interface of security appliances, thereby resulting in unauthorized actions or data exposure.
What’s the issue?
The decisive factor that creates much trouble with regard to CVE-2020-3580 is that it provides for injecting and executing malicious scripts in the web management interface of ASA and FTD devices. Thus, this vulnerability allows an attacker, when successfully exploited, to manipulate the user interface or steal session cookies or perform any other action without detection. Since these specific devices are one of the important elements in maintaining enterprise network security, the aftereffects of a successful attack could be highly critical with respect to the overall security posture of the affected organization.
Background and Context
Background on the vulnerability
CVE-2020-3580 was found in the year 2020 when some security review was conducted for Cisco ASA and FTD software. Cisco ASA is extensively used for firewall, VPN concentrator, and intrusion prevention system purposes, whereas FTD unifies firewall, VPN, and advanced threat protection. The vulnerability occurs as a consequence of incorrect input sanitization provided by users in the web management interface, which an attacker can leverage to inject malicious scripts that will be executed upon the interaction of a user with the vulnerable interface.
Description of the Vulnerability | CVE-2020-3580
The vulnerability is a consequence of the inability of Cisco ASA and FTD’s web services interface to perform proper sanitization of user input before it gets rendered inside the browser. This is especially sent into a situation whereby an attacker might successfully inject scripts that are executed within the user’s browser session if there is interaction with input fields or parameters not correctly sanitized in that particular web interface. A vulnerability of this sort typically results in XSS attacks, allowing the malicious script to manipulate DOM, steal sensitive information, or unauthorized acts.
Root Cause Analysis
At the root of the CVE-2020-3580 vulnerability lies the fact that Cisco ASA and FTD devices do not sufficiently sanitize user input within their web management interface. User-supplied input, either via parameters or form fields, might be reflected back in the browser without proper escaping or validation, hence opening up possibilities for attacks against cross-site scripting. To begin with, it is pretty alarming to find such a vulnerability in devices commonly used to secure significant network infrastructure.
Impact and Exploitation
The impact of CVE-2020-3580
CVE-2020-3580 can be exploited to cause the following significant impacts:
Cross-Site Scripting: Of all the above, the most critical impact is XSS, which would introduce and execute malicious scripts via the web management interface of Cisco ASA and FTD devices. Consequently, this may result in unauthorized actions being executed, data being stolen, or further compromising the security appliance.
Session Hijacking: Using XSS, an attacker may hijack the session cookies or tokens and thereby impersonate that legitimate user to receive unauthorized access to the web interface.
User Interface Manipulation: Attackers can manipulate the web interface in a manner that would mislead administrators into believing certain things are happening when they are not, or into disclosing sensitive information via actions they think appropriate under those circumstances.
Exploit
To successfully exploit CVE-2020-3580, an attacker should prepare a malicious payload that can be injected into a vulnerable input field or parameter in the web management interface. The steps included in the exploitation are:
- Identifying a target Cisco ASA or FTD device with the vulnerable web services interface exposed.
- Crafting a malicious script designed to exploit the XSS vulnerability.
- Injecting this script into the web interface, typically by tricking an administrator into interacting with a malicious link or form.
- When the script executes, it can perform actions within the administrator’s session, such as stealing cookies or manipulating the interface.
In-the-Wild Attacks
There have been few reports of in-the-wild exploitation of CVE-2020-3580. XSS vulnerabilities are generally targeted in the context where administrative interfaces are exposed to the internet or untrusted users. Those organizations that are on vulnerable versions of Cisco ASA and FTD and have failed to apply patches are most at risk.
Vulnerable code/package in the application
The vulnerable code exists in the web services interface of Cisco ASA and FTD software. The vulnerability is due to insufficient input handling and sanitization of inputs in certain sections of the web interface. Affected versions include any releases of Cisco ASA and FTD software prior to the release of patches issued by Cisco to address this vulnerability.
Statistics on vulnerability
While specific exploitation statistics for CVE-2020-3580 are not widely available, the vulnerability’s presence in widely used security appliances like Cisco ASA and FTD makes it a concern for organizations across various industries. The potential impact on critical network infrastructure further emphasizes the need for prompt remediation.
Mitigation and Remediation
Mitigating CVE-2020-3580
Organizations can mitigate the risks associated with CVE-2020-3580 by:
- Applying Patches: Cisco has released patches to address this vulnerability. It is essential to update all affected devices to the latest software versions to prevent exploitation.
- Limiting Access to the Web Interface: Restricting access to the web management interface to trusted IP addresses or using a VPN can reduce the risk of exploitation by unauthorized users.
- Implementing Input Validation: Ensuring that all user input is properly validated and sanitized before being processed by the web interface can help prevent XSS attacks.
Patch and Bypass: Fixes Added for CVE-2020-3580
The CVE-2020-3580 patch entails some changes in how user input to Cisco ASA and FTD web interfaces gets processed. Improved input sanitization and its validation are part of the update, which does not let the execution of malicious scripts take place. As for protection, one should make sure their devices have the latest versions of the software.
Proactive response
Therefore, proactive security would include periodic software updates, administrative interface security audits, and the implementation of best practices in secure input handling. Training administrators is also required in recognizing any potential phishing or social engineering attempts that could be utilized to exploit XSS.
Proof of Concept (POC)
A possible PoC for CVE-2020-3580 involves injecting a malignant script into the web management interface of a Cisco ASA or FTD device, such as:
html –
<img src=x onerror="alert('XSS')">This payload, when injected into a vulnerable input field, triggers an alert, demonstrating the XSS vulnerability.
Real-world Impact and Response
Timeline/changelog
- October 2020: Discovery of CVE-2020-3580 during a security review of Cisco ASA and FTD software.
- October 2020: Public disclosure of the vulnerability and release of patches by Cisco to address the issue.
- November 2020: Continued advisories issued to organizations to update their devices and secure their web interfaces against XSS attacks.
Observed Activity
Since the date of its publication, CVE-2020-3580 has been in the crosshairs of security researchers, with active exploitation reports very limited publicly. This vulnerability being present in critical security infrastructure has motivated organisations to patch and lock down devices quickly.
Mass Scanning
So far, there have not been any widespread reports of mass scanning specifically targeting CVE-2020-3580. However, attackers will often scan for open administrative interfaces, and vulnerable devices running Cisco ASA or FTD may be at risk if not well secured.
Vulnerable Server Discovery
These attackers will find vulnerable devices by means of targeted scanning or analyzing network traffic for the presence of outdated versions of Cisco ASA or FTD. It is advisable that administrators make proper configurations in their devices and allow access to the web interface only from trusted networks.
Reasoning and Scoring
Corporate networks impacted globally
This vulnerability, CVE-2020-3580, absolutely affects the global corporate networks, as industries such as finance, transportation, energy, manufacturing, and others extensively use Cisco ASA and FTD to keep the security of their respective networks intact. This vulnerability can be utilized to conduct XSS attacks, thereby compromising administrative sessions and disrupting security operations.
Corporate numbers impacted by countries
- United States: Extensive use of Cisco ASA and FTD in enterprise environments, with many organizations potentially at risk.
- Europe: Significant adoption of Cisco security appliances in technology, finance, and critical infrastructure sectors, leading to potential exposure.
- Asia: Widespread use of Cisco ASA and FTD in industries where secure network management is critical.
Conclusion
Who should be paying attention to this?
Network administrators, cybersecurity professionals, and organizations that use Cisco ASA or FTD for network security should prioritize attention to CVE-2020-3580. Ensuring that these devices are patched and secure is critical for maintaining the integrity of the network’s security infrastructure.
Who is exploiting it and how?
CVE-2020-3580 has been exploited by attackers who identify vulnerable Cisco ASA or FTD devices with exposed web management interfaces. These attackers craft malicious scripts designed to exploit the XSS vulnerability, leading to session hijacking, unauthorized actions, and potential disruption of security operations.
How are things likely to develop?
As more organizations apply patches and secure their devices, the risk of widespread exploitation decreases. However, systems that remain unpatched are still vulnerable to attack, and the potential for targeted exploitation remains a concern. Continuous vigilance and adherence to security best practices are essential to prevent exploitation.
How long has it been around?
CVE-2020-3580 was discovered and disclosed in October 2020, but the underlying issue with improper input sanitization may have existed in Cisco ASA and FTD software for some time before its discovery. This highlights the importance of regular security reviews and updates to address potential vulnerabilities in critical security infrastructure.
