CVE-2020-3259 Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD): information leak
In plain words: The program reveals information it should keep private. Leaked secrets — tokens, passwords or memory contents — that help a bigger attack.
Confirmed exploited by CISA on · US federal patch deadline Mar 7, 2024
What to do
- Install Cisco's security update for Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD). If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Patch edge devices first — attackers often start scanning for them within hours of a fix.
- Never expose the device's admin page to the internet.
- After patching a device that was exposed, follow the vendor's compromise checks, end active sessions and change passwords.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: They face the internet and guard the whole network, so a flaw here can hand attackers a way in — and these devices usually run no antivirus, so break-ins go unnoticed.
The details
- Official name
- Cisco ASA and FTD Information Disclosure Vulnerability
- Product
- Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
- CISA description
- Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an information disclosure vulnerability. An attacker could retrieve memory contents on an affected device, which could lead to the disclosure of confidential information due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. This vulnerability affects only specific AnyConnect and WebVPN configurations.
- Type of flaw
- Information leak (CWE-200)
- Confirmed exploited
- Feb 15, 2024 — known to be used in ransomware attacks
- US federal patch deadline
- Mar 7, 2024
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Answering about CVE-2020-3259 ·
Questions about CVE-2020-3259
Is CVE-2020-3259 being exploited?
Yes. CISA added CVE-2020-3259 to its Known Exploited Vulnerabilities catalog on Feb 15, 2024, which means there is reliable evidence of real-world attacks, including by ransomware groups.
How do I fix CVE-2020-3259?
Install Cisco's security update for Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD). If no update exists, follow the vendor's workaround or stop using the product until one ships. Patch edge devices first — attackers often start scanning for them within hours of a fix.
Am I affected by CVE-2020-3259?
Only if you use Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD). Aimed mostly at company systems — you are affected through the companies you use, not your own phone.