CVE-2021-1256

MEDIUMNVD 6.06.0—
EchelonGraph scoreMEDIUM confidence

Score 6.0 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 6.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.0Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
6.0
EG Score
6.0(medium)
EG Risk
—
EPSS
39.7%
KEV
Not listed

Published

April 29, 2021

Last Modified

November 21, 2024

References (4)

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 46× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 22:42 UTCEG score recompute
  2. 2026-07-22 14:05 UTCEPSS rescore
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  68. 2026-05-26 17:15 UTCEG score recompute
  69. 2026-05-26 17:15 UTCGHSA enrichment
  70. 2026-05-26 13:42 UTCEPSS rescore
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Frequently asked(5)

What is CVE-2021-1256?
CVE-2021-1256 is a medium vulnerability published on April 29, 2021. 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…
When was CVE-2021-1256 disclosed?
CVE-2021-1256 was first published in the National Vulnerability Database on April 29, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-1256 actively exploited?
CVE-2021-1256 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 39.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-1256?
CVE-2021-1256 has a CVSS v3 base score of 6.0 (NVD).
How do I remediate CVE-2021-1256?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-1256, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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