CVE-2021-1256Cisco Firepower Threat Defense Software Command File Overwrite Vulnerability
- 6.0MediumCVSS base score
- 0.50%Exploitation in 30 daysEPSS · top 56% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A vulnerability in the CLI of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to overwrite files on the file system of an affected device by using directory traversal techniques. A successful exploit could cause system instability if important system files are overwritten. This vulnerability is due to insufficient validation of user input for the file path in a specific CLI command. An attacker could exploit this vulnerability by logging in to a targeted device and issuing a specific CLI command with crafted user input. A successful exploit could allow the attacker to overwrite arbitrary files on the file system of the affected device. The attacker would need valid user credentials on the device.
Timeline
ID reserved
By cisco
- 6 months later
· 6 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Medium6.0 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H |
| NVDNVD · Modified | 3.1 | Medium6.0 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.50% · top 56% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.0.
Affected products
Cisco · Cisco Firepower Threat Defense Software
- affected n/a
What to do
Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
References
References2
- 20210428 Cisco Firepower Threat Defense Software Command File Overwrite Vulnerability (opens in a new tab)vendor-advisoryx_refsource_CISCOx_transferred
- https://kc.mcafee.com/corporate/index?page=content&id=SB10382 (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-6723 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-1256)Record last updated .