CVE-2021-34741: cisco asyncos
Vulnerability summary
CVE-2021-34741 is a high (CVSS 7.5) vulnerability in cisco asyncos. EPSS estimates a 1.29% chance of exploitation in the next 30 days, higher than 69.8% of scored vulnerabilities.
Timeline
- 04-11-2021PublishedVulnerability first disclosed.
- 07-11-2024Last modifiedVulnerability information updated.
Description
A vulnerability in the email scanning algorithm of Cisco AsyncOS software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to perform a denial of service (DoS) attack against an affected device. This vulnerability is due to insufficient input validation of incoming emails. An attacker could exploit this vulnerability by sending a crafted email through Cisco ESA. A successful exploit could allow the attacker to exhaust all the available CPU resources on an affected device for an extended period of time, preventing other emails from being processed and resulting in a DoS condition.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
1.29%
Chance of exploitation in the next 30 days
Percentile
70%
Versus all other CVEs
30-day change
0.00 pp
From 1.29% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Cisco2 products
- asyncos< 13.0.4 | 13.5.3-010 | 13.7.0-093
- cisco email security appliance (esa)n/a
1 vendor · 2 products
References
1 links- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-dos-JOm9ETfOVendor AdvisoryX Refsource CISCO