CVE-2020-3259 | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Information Disclosure Vulnerability

Exp

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.

Published: 2020-05-06 Last update: 2025-10-28 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-3259 is rated Critical Active Threat (89.1/100): CVSS High severity, with high exploitation likelihood (EPSS 69.73%, 99th percentile). CISA KEV confirms active exploitation (added 2024-02-15) affecting Cisco / Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD). a weakness (CWE-200) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2020-3259

Name: Cisco ASA and FTD Information Disclosure Vulnerability · CISA KEV detail

Exploit added: 2024-02-15

Action due: 2024-03-07

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Exploit prediction scoring system (EPSS) score for CVE-2020-3259

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-22 70.15% 69.73% -0.42%
2 2026-04-21 69.73% 70.15% +0.42%
3 2026-03-04 — 69.73% —

Full EPSS history (66 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-3259

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-3259

Affected software / configurations for CVE-2020-3259

Vendor Product Version Raw CPE
cisco firepower_threat_defense >= 6.2.3, < 6.2.3.16 cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
cisco firepower_threat_defense >= 6.3.0, < 6.3.0.6 cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
cisco firepower_threat_defense >= 6.4.0, < 6.4.0.9 cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
cisco firepower_threat_defense >= 6.5.0, < 6.5.0.5 cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
cisco adaptive_security_appliance_software >= 9.8, < 9.8.4.20 cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco adaptive_security_appliance_software >= 9.9, < 9.9.2.67 cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco adaptive_security_appliance_software >= 9.10, < 9.10.1.40 cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco adaptive_security_appliance_software >= 9.12, < 9.12.3.9 cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cisco adaptive_security_appliance_software >= 9.13, < 9.13.1.10 cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*

References for CVE-2020-3259

cvelogic Threat Intelligence