CyberSecBulletin
CVE-2020-3259Exploited in the wildNVD status: Analyzed

Cisco ASA and FTD Information Disclosure

Published Updated By the CyberSecBulletin desk

CVE-2020-3259 is a high-severity exposure of sensitive information to an unauthorized actor vulnerability in Cisco Adaptive Security Appliance (ASA) Software from Cisco, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. CISA added it to the Known Exploited Vulnerabilities catalogue on February 15, 2024, which means attacks have been observed in the wild, including in ransomware campaigns.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update firepower_threat_defense to 6.2.3.16 or 6.3.0.6 or 6.4.0.9 or 6.5.0.5, whichever matches your release line, or a later version.
  2. Update adaptive_security_appliance_software to 9.8.4.20 or 9.9.2..67 or 9.10.1.40 or 9.12.3.9, whichever matches your release line, or a later version.
  3. Update Secure Firewall Threat Defense to 6.2.3.16 or 6.3.0.6 or 6.4.0.9 or 6.5.0.5, whichever matches your release line, or a later version.
  4. CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
  5. Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
  6. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco Adaptive Security Appliance (ASA) SoftwareNot specified in the recordNot stated
Ciscofirepower_threat_defense6.2.3 up to, but not including, 6.2.3.16; 6.3.0 up to, but not including, 6.3.0.6; 6.4.0 up to, but not including, 6.4.0.9; 6.5.0 up to, but not including, 6.5.0.56.2.3.16, 6.3.0.6, 6.4.0.9, 6.5.0.5
Ciscoadaptive_security_appliance_software9.8 up to, but not including, 9.8.4.20; 9.9 up to, but not including, 9.9.2..67; 9.10 up to, but not including, 9.10.1.40; 9.12 up to, but not including, 9.12.3.9; 9.13 up to, but not including, 9.13.1.109.8.4.20, 9.9.2..67, 9.10.1.40, 9.12.3.9, 9.13.1.10
CiscoSecure Firewall Threat Defense6.2.3 up to, but not including, 6.2.3.16; 6.3.0 up to, but not including, 6.3.0.6; 6.4.0 up to, but not including, 6.4.0.9; 6.5.0 up to, but not including, 6.5.0.56.2.3.16, 6.3.0.6, 6.4.0.9, 6.5.0.5

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighNVD
CVSS 3.07.5HighCNA (cisco.com)
CVSS 2.05.0MediumNVD

Official description

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to retrieve memory contents on an affected device, which could lead to the disclosure of confidential information. The vulnerability is due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. An attacker could exploit this vulnerability by sending a crafted GET request to the web services interface. A successful exploit could allow the attacker to retrieve memory contents, which could lead to the disclosure of confidential information. Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

How developers prevent this class of flaw

  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities (CWE-200)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: partial).
  3. Added to CISA's Known Exploited Vulnerabilities catalogue.
  4. Deadline for US federal agencies to remediate, set by CISA.
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Cisco Adaptive Security Appliance (ASA) Software

All Cisco Adaptive Security Appliance (ASA) Software vulnerabilities

Recent Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities

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