CVE-2021-1495: cisco cisco firepower threat defense software
Vulnerability summary
CVE-2021-1495 is a medium (CVSS 5.8) vulnerability in cisco cisco firepower threat defense software. EPSS estimates a 1.73% chance of exploitation in the next 30 days, higher than 77.1% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 3Timeline
- 29-04-2021PublishedVulnerability first disclosed.
- 08-11-2024Last modifiedVulnerability information updated.
Description
Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The vulnerability is due to incorrect handling of specific HTTP header parameters. An attacker could exploit this vulnerability by sending crafted HTTP packets through an affected device. A successful exploit could allow the attacker to bypass a configured file policy for HTTP packets and deliver a malicious payload.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NDiffers
- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NDiffers
EPSS trend
Probability
1.73%
Chance of exploitation in the next 30 days
Percentile
77%
Versus all other CVEs
30-day change
+0.01 pp
From 1.71% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Cisco3 products
- cisco firepower threat defense softwaren/a
- ios_xe≥ 16.12, < 16.12.5 | ≥ 17.1, < 17.3.3 | ≥ 17.4, < 17.4.1
- secure_firewall_threat_defense< 6.4.0.12 | ≥ 6.5.0, < 6.6.4 | ≥ 6.7.0, < 6.7.0.2
Snort1 product
- snort< 2.9.17.1
Ubuntu1 product
- snortAll versions (No fix recorded)
3 vendors · 5 products
References
5 links
- www.debian.org/security/2023/dsa-5354Vendor Advisory