How severe is CVE-2009-0841?

CVE-2009-0841 has a CVSS 2.0 base score of 10.0, rated critical severity.

Is CVE-2009-0841 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0841?

CVE-2009-0841 primarily affects Osgeo Mapserver. In total, 42 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0841?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2009-0841 published?

CVE-2009-0841 was published on 2009-03-31 and last updated on 2026-06-16.

CVE-2009-0841

CVE-2009-0841 is a critical-severity vulnerability in Osgeo Mapserver with a CVSS 2.0 base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.

Key facts

Severity: Critical (CVSS 2.0 base score 10.0)
EPSS exploit prediction: 5% (92nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-22
Affected product: Osgeo Mapserver
Published: 2009-03-31
Last modified: 2026-06-16

Description

Directory traversal vulnerability in mapserv.c in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2, when running on Windows with Cygwin, allows remote attackers to create arbitrary files via a .. (dot dot) in the id parameter.

Frequently asked questions

What is CVE-2009-0841?: Directory traversal vulnerability in mapserv.c in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2, when running on Windows with Cygwin, allows remote attackers to create arbitrary files via a .. (dot dot) in the id parameter.
How severe is CVE-2009-0841?: CVE-2009-0841 has a CVSS 2.0 base score of 10.0, rated critical severity.
Is CVE-2009-0841 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0841?: CVE-2009-0841 primarily affects Osgeo Mapserver. In total, 42 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0841?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2009-0841 published?: CVE-2009-0841 was published on 2009-03-31 and last updated on 2026-06-16.

References

Affected products (42)

cpe:2.3:a:osgeo:mapserver:4.2.0:beta1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.4.0:*:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.4.0:beta1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.4.0:beta2:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.4.0:beta3:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.6.0:*:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.6.0:beta1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.6.0:beta2:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.6.0:beta3:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.6.0:rc1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.8.0:beta1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.8.0:beta2:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.8.0:beta3:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.8.0:rc1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.8.0:rc2:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.10.0:*:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.10.0:beta1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.10.0:beta2:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.10.0:beta3:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.10.0:rc1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.10.1:*:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.10.2:*:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:4.10.3:*:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.0.0:*:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.0.0:beta1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.0.0:beta2:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.0.0:beta3:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.0.0:beta4:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.0.0:beta5:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.0.0:beta6:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.0.0:rc1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.0.0:rc2:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.2.0:*:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.2.0:beta1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.2.0:beta2:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.2.0:beta3:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.2.0:beta4:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.2.0:rc1:*:*:*:*:*:*
cpe:2.3:a:osgeo:mapserver:5.2.1:*:*:*:*:*:*:*
cpe:2.3:a:umn:mapserver:4.0:*:*:*:*:*:*:*

More vulnerabilities in Osgeo Mapserver

CVE-2010-2540 — Critical (CVSS 10.0): mapserv.c in mapserv in MapServer before 4.10.6 and 5.x before 5.6.4 does not properly restrict the use of CGI…
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CVE-2009-0840 — Critical (CVSS 10.0): Heap-based buffer underflow in the readPostBody function in cgiutil.c in mapserv in MapServer 4.x before 4.10.4 and 5.x…
CVE-2009-0839 — Critical (CVSS 10.0): Stack-based buffer overflow in mapserv.c in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2, when the…

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