5.8

CVE-2021-1534: cisco asyncos Improper Input Validation

CVSS: 5.8v3.1MediumModified
Published 06-10-2021Last modified 07-11-2024
Open JSON

Vulnerability summary

CVE-2021-1534 is a medium (CVSS 5.8) Improper Input Validation vulnerability in cisco asyncos. EPSS estimates a 1.07% chance of exploitation in the next 30 days, higher than 64.2% of scored vulnerabilities.

Overall risk
23/100
0100
Low · default modelHow is this calculated?
CVSS score
5.8/10
010
Medium · v3.1 (CVE.org)
EPSS score
1.07%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 06-10-2021
    PublishedVulnerability first disclosed.
  2. 07-11-2024
    Last modifiedVulnerability information updated.

Description

A vulnerability in the antispam protection mechanisms of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the URL reputation filters on an affected device. This vulnerability is due to improper processing of URLs. An attacker could exploit this vulnerability by crafting a URL in a particular way. A successful exploit could allow the attacker to bypass the URL reputation filters that are configured for an affected device, which could allow malicious URLs to pass through the device.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

1.07%

Chance of exploitation in the next 30 days

Percentile

64%

Versus all other CVEs

30-day change

0.00 pp

From 1.07% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.07%

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

Cisco2 products

1 vendor · 2 products

References

1 links