CVE-2009-5023

The (1) dshield.conf, (2) mail-buffered.conf, (3) mynetwatchman.conf, and (4) mynetwatchman.conf actions in action.d/ in Fail2ban before 0.8.5 allows local users to write to arbitrary files via a symlink attack on temporary files with predictable names, as demonstrated by /tmp/fail2ban-mail.txt.

Published: 2014-06-10 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-5023 is rated Low Risk (22.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2009-5023

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-30 0.05% 0.05% -0.00%
2 2025-03-29 0.05% 0.05% +0.00%
3 2025-03-23 — 0.05% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-5023

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.7 2.0 MEDIUM
AV:L/AC:M/Au:N/C:N/I:C/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:N)
No availability impact.
 3.4 6.9 [email protected]

Weakness enumeration for CVE-2009-5023

OS Trackers for CVE-2009-5023

vendor priority summary link
debian low CVE-2009-5023 low priority: Debian including 1 source packages (fail2ban), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2009-5023
gentoo normal CVE-2009-5023: 1 GLSA(s) (201406-03), 1 atom(s) (net-analyzer/fail2ban); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2009-5023
ubuntu low CVE-2009-5023 low priority: Ubuntu including 1 source packages (fail2ban), 10 status rows across 10 suites (hardy, lucid, maverick, natty, oneiric, precise, quantal, raring, saucy, upstream): not-affected 5, ignored 4, released 1. https://ubuntu.com/security/CVE-2009-5023

Affected software / configurations for CVE-2009-5023

Vendor Product Version Raw CPE
fail2ban fail2ban <= 0.8.4 cpe:2.3:a:fail2ban:fail2ban:*:*:*:*:*:*:*:*
fail2ban fail2ban 0.1.0 cpe:2.3:a:fail2ban:fail2ban:0.1.0:*:*:*:*:*:*:*
fail2ban fail2ban 0.1.1 cpe:2.3:a:fail2ban:fail2ban:0.1.1:*:*:*:*:*:*:*
fail2ban fail2ban 0.1.2 cpe:2.3:a:fail2ban:fail2ban:0.1.2:*:*:*:*:*:*:*
fail2ban fail2ban 0.3.0 cpe:2.3:a:fail2ban:fail2ban:0.3.0:*:*:*:*:*:*:*
fail2ban fail2ban 0.3.1 cpe:2.3:a:fail2ban:fail2ban:0.3.1:*:*:*:*:*:*:*
fail2ban fail2ban 0.4.0 cpe:2.3:a:fail2ban:fail2ban:0.4.0:*:*:*:*:*:*:*
fail2ban fail2ban 0.4.1 cpe:2.3:a:fail2ban:fail2ban:0.4.1:*:*:*:*:*:*:*
fail2ban fail2ban 0.5.0 cpe:2.3:a:fail2ban:fail2ban:0.5.0:*:*:*:*:*:*:*
fail2ban fail2ban 0.5.1 cpe:2.3:a:fail2ban:fail2ban:0.5.1:*:*:*:*:*:*:*
fail2ban fail2ban 0.5.2 cpe:2.3:a:fail2ban:fail2ban:0.5.2:*:*:*:*:*:*:*
fail2ban fail2ban 0.5.3 cpe:2.3:a:fail2ban:fail2ban:0.5.3:*:*:*:*:*:*:*
fail2ban fail2ban 0.5.4 cpe:2.3:a:fail2ban:fail2ban:0.5.4:*:*:*:*:*:*:*
fail2ban fail2ban 0.5.5 cpe:2.3:a:fail2ban:fail2ban:0.5.5:*:*:*:*:*:*:*
fail2ban fail2ban 0.6.0 cpe:2.3:a:fail2ban:fail2ban:0.6.0:*:*:*:*:*:*:*
fail2ban fail2ban 0.6.1 cpe:2.3:a:fail2ban:fail2ban:0.6.1:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.0 cpe:2.3:a:fail2ban:fail2ban:0.7.0:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.1 cpe:2.3:a:fail2ban:fail2ban:0.7.1:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.2 cpe:2.3:a:fail2ban:fail2ban:0.7.2:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.3 cpe:2.3:a:fail2ban:fail2ban:0.7.3:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.4 cpe:2.3:a:fail2ban:fail2ban:0.7.4:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.5 cpe:2.3:a:fail2ban:fail2ban:0.7.5:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.6 cpe:2.3:a:fail2ban:fail2ban:0.7.6:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.7 cpe:2.3:a:fail2ban:fail2ban:0.7.7:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.8 cpe:2.3:a:fail2ban:fail2ban:0.7.8:*:*:*:*:*:*:*
fail2ban fail2ban 0.7.9 cpe:2.3:a:fail2ban:fail2ban:0.7.9:*:*:*:*:*:*:*
fail2ban fail2ban 0.8.0 cpe:2.3:a:fail2ban:fail2ban:0.8.0:*:*:*:*:*:*:*
fail2ban fail2ban 0.8.1 cpe:2.3:a:fail2ban:fail2ban:0.8.1:*:*:*:*:*:*:*
fail2ban fail2ban 0.8.2 cpe:2.3:a:fail2ban:fail2ban:0.8.2:*:*:*:*:*:*:*
fail2ban fail2ban 0.8.3 cpe:2.3:a:fail2ban:fail2ban:0.8.3:*:*:*:*:*:*:*

References for CVE-2009-5023

cvelogic Threat Intelligence