`CVE-2020-3259`

Affected software	2 products, listed below
Severity	7.5 High CVSS 3.1 3 scores
Weakness	Information exposure (CWE-200)
Published	6 May 2020
Updated	12 Aug 2026

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.

Exploitation status

Exploited

Confirmed real-world exploitation.

CISA KEV listed Confirmed exploitation in the wild. Added 2024-02-15 · remediation due 2024-03-07 · ransomware use: known
VulnCheck KEV listed Exploitation reported in the wild. 33 citations · honeypot sightings · earliest 2024-01-29.
CISA Vulnrichment no assessment published
Indexed PoC none indexed
EPSS 72% chance in 30 days A model's forecast, not a report of exploitation. Higher than 99% of all scored CVEs.

VulnCheck KEV

Exploitation evidence from VulnCheck Known Exploited Vulnerabilities (VulnCheck KEV), used under VulnCheck's community terms. View CVE-2020-3259 in VulnCheck (free account), which lists 28 more citations not shown here.

Evidence	Source	Detail	Date
Honeypot sighting	Shadowserver honeypots	Exploitation attempts seen on 34 days	2025-07-12 to 2026-11-06
Reported exploitation	truesec.com	/hub/blog/akira-ransomware-and-exploitation-of-cisco-anyconnect-vulnerability-cve-2020-3259	2024-01-29
Reported exploitation	cisa.gov	/sites/default/files/feeds/known_exploited_vulnerabilities.json	2024-02-15
Reported exploitation	cisa.gov	/news-events/cybersecurity-advisories/aa24-109a	2024-04-18
Reported exploitation	thehackernews.com	/2024/04/akira-ransomware-gang-extorts-42.html	2024-04-19
Reported exploitation	fortiguard.com	/outbreak-alert/akira-ransomware	2024-04-23

Evidence

Source

Detail

Date

Honeypot sighting

Shadowserver honeypots

Exploitation attempts seen on 34 days

2025-07-12 to 2026-11-06

Reported exploitation

truesec.com

/hub/blog/akira-ransomware-and-exploitation-of-cisco-anyconnect-vulnerability-cve-2020-3259

2024-01-29

Reported exploitation

cisa.gov

/sites/default/files/feeds/known_exploited_vulnerabilities.json

2024-02-15

Reported exploitation

cisa.gov

/news-events/cybersecurity-advisories/aa24-109a

2024-04-18

Reported exploitation

thehackernews.com

/2024/04/akira-ransomware-gang-extorts-42.html

2024-04-19

Reported exploitation

fortiguard.com

/outbreak-alert/akira-ransomware

2024-04-23

Waratek protection

Outside Waratek scope

A Java vulnerability, but not one Waratek protects. It affects only Java on a user's desktop (applets, Web Start, JavaFX, the installer), sits in a product the Waratek agent can't be installed into, or is in a package we don't expect in business applications. The decision below says which.

Protection none
Action not pursued none
Review human Researcher
Record active

Decided by	Manual classification of this CVE in the legacy dataset
Finding	A manual classification set this CVE's status to Outside Waratek scope, but the CVE names a tracked product.

Decided by

Manual classification of this CVE in the legacy dataset

Finding

A manual classification set this CVE's status to Outside Waratek scope, but the CVE names a tracked product.

CVSS

7.5 HIGH v3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N 3 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

Version Score Band Vector Assigner Type

CVSS 3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N NVD Primary published

CVSS 3.0 7.5 HIGH CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N psirt@cisco.com Secondary

CVSS 2.0 5.0 none AV:N/AC:L/Au:N/C:P/I:N/A:N NVD Primary

Version	Score	Band	Vector	Assigner	Type
CVSS 3.1	7.5	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`	NVD	Primary	published
CVSS 3.0	7.5	HIGH	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`	psirt@cisco.com	Secondary
CVSS 2.0	5.0	none	`AV:N/AC:L/Au:N/C:P/I:N/A:N`	NVD	Primary

Affected software and releases

Products and versions

2 products, 9 version entries

Source	Vendor	Product	Scheme	Affected versions
nvd	cisco	adaptive security appliance software	generic	≥ 9.8 and ＜ 9.8.4.20 · ≥ 9.9 and ＜ 9.9.2.67 · ≥ 9.10 and ＜ 9.10.1.40 · ≥ 9.12 and ＜ 9.12.3.9 · ≥ 9.13 and ＜ 9.13.1.10
nvd	cisco	secure firewall threat defense	generic	≥ 6.2.3 and ＜ 6.2.3.16 · ≥ 6.3.0 and ＜ 6.3.0.6 · ≥ 6.4.0 and ＜ 6.4.0.9 · ≥ 6.5.0 and ＜ 6.5.0.5

Source

Vendor

Product

Scheme

Affected versions

nvd

cisco

adaptive security appliance software

generic

≥ 9.8 and ＜ 9.8.4.20 · ≥ 9.9 and ＜ 9.9.2.67 · ≥ 9.10 and ＜ 9.10.1.40 · ≥ 9.12 and ＜ 9.12.3.9 · ≥ 9.13 and ＜ 9.13.1.10

nvd

cisco

secure firewall threat defense

generic

≥ 6.2.3 and ＜ 6.2.3.16 · ≥ 6.3.0 and ＜ 6.3.0.6 · ≥ 6.4.0 and ＜ 6.4.0.9 · ≥ 6.5.0 and ＜ 6.5.0.5

References

URL	Tags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-info-disclose-9eJtycMB
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3259	US Government Resource

URL

Timeline

Published	2020-05-06	By the CVE Program.
VulnCheck KEV: earliest evidence	2024-01-29	Date of the oldest evidence of exploitation in VulnCheck KEV's record. VulnCheck does not publish the date it listed the CVE.
Added to CISA KEV	2024-02-15	Listed in CISA's Known Exploited Vulnerabilities catalog.
NVD record modified	2026-08-12	NVD's own last-modified date for this record.
VulnCheck KEV: latest evidence	2026-11-06	Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.

Published

2020-05-06

By the CVE Program.

VulnCheck KEV: earliest evidence

2024-01-29

Date of the oldest evidence of exploitation in VulnCheck KEV's record. VulnCheck does not publish the date it listed the CVE.

Added to CISA KEV

2024-02-15

Listed in CISA's Known Exploited Vulnerabilities catalog.

NVD record modified

2026-08-12

NVD's own last-modified date for this record.

VulnCheck KEV: latest evidence

2026-11-06

Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.

How VRT decided (5 of 24 rules ran)

5 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification no match A researcher's recorded decision for this specific CVE

5 manual classification decided it matched Outside Waratek scope Found in legacy manual classifications

6 non-java-upstream not reached A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component not reached The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side not reached Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven not reached An OSV.dev record of this CVE affecting a package published to Maven Central. When every such package is one business applications do not use (Minecraft mods and launchers, Fastjson) and no tracked product is named by CPE, it settles the CVE as Outside Waratek scope instead

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint not reached A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

18 open-source-maven not reached The affected package being open source on Maven, so the fix can be read

19 poc-derivable not reached An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit not reached Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match not reached A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc not reached Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold not reached Medium or Low severity, no CISA or VulnCheck KEV listing, no PoC clearing the evidence bar, no CISA verdict, no Oracle advisory

24 no-exploit-published not reached Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

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