8.6

CVE-2021-1501: cisco adaptive_security_appliance_software Insufficient Session Expiration

CVSS: 8.6v3.1HighModified
Published 29-04-2021Last modified 08-11-2024
Open JSON

Vulnerability summary

CVE-2021-1501 is a high (CVSS 8.6) Insufficient Session Expiration vulnerability in cisco adaptive_security_appliance_software. EPSS estimates a 1.35% chance of exploitation in the next 30 days, higher than 71% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.6/10
010
High · v3.1 (CVE.org)
EPSS score
1.35%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 29-04-2021
    PublishedVulnerability first disclosed.
  2. 08-11-2024
    Last modifiedVulnerability information updated.

Description

A vulnerability in the SIP inspection engine of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a crash and reload of an affected device, resulting in a denial of service (DoS) condition.The vulnerability is due to a crash that occurs during a hash lookup for a SIP pinhole connection. An attacker could exploit this vulnerability by sending crafted SIP traffic through an affected device. A successful exploit could allow the attacker to cause a crash and reload of the affected device.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

1.35%

Chance of exploitation in the next 30 days

Percentile

71%

Versus all other CVEs

30-day change

+0.01 pp

From 1.34% on 18-09-2026

18-09-202618-10-2026
EPSS score
1.35%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco3 products

1 vendor · 3 products

References

1 links