CVE-2020-20277

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-24. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 26%CVSS: 9.8Exploit: Elevated riskExposed: 0

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

There are multiple unauthenticated directory traversal vulnerabilities in different FTP commands in uftpd FTP server versions 2.7 to 2.10 due to improper implementation of a chroot jail in common.c's compose_abspath function that can be abused to read or write to arbitrary files on the filesystem, leak process memory, or potentially lead to remote code execution.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
65(Track*)
EG Risk 65/100SSVC: Track*

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation40% × 40%
Automatability30% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
26%
EPSS %ILE
98%
KEV
Not listed

Published

December 18, 2020

Last Modified

November 21, 2024

Advisory Details (3)

Auto-updated Sep 20, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit.
github_commit Patch Available

commit 455b47d3756a (troglobit/uftpd)

Patch available: troglobit/uftpd v2.11 (contains commit 455b47d3756a)

https://github.com/troglobit/uftpd/commit/455b47d3756aed162d2d0ef7f40b549f3b5b30fe
generic🟡 PoC Available

Aaron Esau (arinerron)

https://arinerron.com/blog/posts/6
generic

Locked Out | Packet Storm

http://packetstormsecurity.com/files/167908/uftpd-2.10-Directory-Traversal.html

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 28× 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.

Showing the most recent 100 of 140 total refreshes for this CVE.

  1. 2026-09-24 14:00 UTCEPSS rescore
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Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-51000
    First seen Aug 2, 2022

    uftpd 2.10 - Directory Traversal (Authenticated)

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2020-20277?
CVE-2020-20277 is a critical vulnerability published on December 18, 2020. There are multiple unauthenticated directory traversal vulnerabilities in different FTP commands in uftpd FTP server versions 2.7 to 2.10 due to improper implementation of a chroot jail in common.c's compose_abspath function that can be abused to read or write to arbitrary files on the filesystem,…
When was CVE-2020-20277 disclosed?
CVE-2020-20277 was first published in the National Vulnerability Database on December 18, 2020, 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-2020-20277 actively exploited?
CVE-2020-20277 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 26% probability of exploitation in the next 30 days, which ranks it in the top 2.1% of all scored CVEs.
What is the CVSS score of CVE-2020-20277?
CVE-2020-20277 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2020-20277?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-20277, 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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