Is CVE-2009-4491 in the CISA KEV catalog?

No. CVE-2009-4491 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2009-4491?

CVE-2009-4491 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2009-4491?

CVE-2009-4491 has an EPSS score of 13.47% (96th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2009-4491

CRITICALEPSS 96th pctl

9.8

CVSS v3

NVD

Description

thttpd 2.25b0 writes data to a log file without sanitizing non-printable characters, which might allow remote attackers to modify a window's title, or possibly execute arbitrary commands or overwrite files, via an HTTP request containing an escape sequence for a terminal emulator.

CWE-20Improper Input Validation CWE-94Code Injection

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

13.47%probability of exploitation in 30 days

96thpercentile

Very high risk: more likely to be exploited than 96% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.