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
Why It Matters
Analysis dossierWhy It Matters
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.
Immediate Attention
Yes
Unknown
Risk basis: CISA KEV exploitation signal; SOC ecosystem technology relevance; HIGH severity; Known exploitation signal from CISA KEV or ransomware metadata; Source-confirmed exploitation or CISA KEV/ransomware metadata
Affected Products & Remediation
2 source-backed productsVendor or catalog guidance (source)
- CISA KEV: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Known exploitation (source facts)
Only what a source states. Unknown means no source has said either way; it is not "not exploited".
- CISA KEV
- Listed
- Exploited (source statement)
- Yes
- Publicly disclosed (source)
- Unknown
CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Suggested hunting (rule-based inference)
SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.
Matched kev-network-exposure (CVSS AV:N, CISA KEV Listed); network-unauthenticated (CVSS AV:N, CVSS PR:N, CVSS UI:N)
Exposure
- Identify assets with the exact CVE and confirm the affected product/version against the advisory.Telemetry: DeviceTvmSoftwareVulnerabilities · KEV listing raises urgency, but inventory is needed to establish local exposure. · Rule kev-network-exposure
- Identify devices reporting this CVE and note which expose the affected service to untrusted networks.Telemetry: DeviceTvmSoftwareVulnerabilities · A network-reachable, no-privilege vector makes internet-facing instances the first exposure question. · Rule network-unauthenticated
Exploitation evidence
- Review relevant edge or application access logs for unusual requests around the advisory window.Telemetry: CommonSecurityLog · Log review is a hunting hypothesis; KEV listing alone does not show local exploitation. · Rule kev-network-exposure
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Exploitation evidence
- Review inbound connections to the affected service from unexpected sources since the advisory date.Telemetry: DeviceNetworkEvents · Hunting hypothesis from the CVSS vector; it does not show that exploitation occurred. · Rule network-unauthenticated
Response
- Recheck the affected assets after the source-stated mitigation or update is applied.Telemetry: DeviceTvmSoftwareVulnerabilities · A follow-up inventory check verifies local remediation. · Rule kev-network-exposure
CISA KEV Record
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Change History & Source Data
— No recorded material change
- CNA / source
- psirt@cisco.com
- Record status · verification
- UPDATED · CISA KEV confirmed
- CPE
- cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*, cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
Evidence & Provenance
Linked by the query's stored exact CVE association. Review required tables and validation status before use.
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2020-3259"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel desc