Cisco Adaptive Security Appliance (ASA) Cross-Site Scripting (XSS) Vulnerability

Cross-site scripting (XSS) vulnerability in the WebVPN login page in Cisco Adaptive Security Appliance (ASA) Software allows remote attackers to inject arbitrary web script or HTML via an unspecified parameter, aka Bug ID CSCun19025.

CheckOps priority index

4.6/10 Patch within 7 days

Severity5.4

Probability2.3

Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 22.6% higher than 97.7% of CVEs

CVSS 3.1 5.4 AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:

Exploited for 721 days 12 Nov 2024

CISA due date 03 Dec 2024 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

KEV catalog (CISA)12 Nov 2024
Exploited in EUVD (ENISA)12 Nov 2024
Used by ransomwareno
EPSS above 10 %22.6%
No account, over the networkno

What to do

Fix

Apply the vendor’s fix as soon as it is available.

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

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Affected products

Adaptive Security Appliance (ASA)

Weaknesses (CWE)

CWE-79

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

19 Mar 2014
Published
12 Nov 2024
Exploitation reported (ENISA)
12 Nov 2024
Added to the KEV catalog
03 Dec 2024
CISA remediation due date
28 Sept 2026
EPSS peak: 22.6%

References

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