How severe is CVE-2009-0641?

CVE-2009-0641 has a CVSS 2.0 base score of 9.3, rated critical severity.

Is CVE-2009-0641 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (95th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0641?

CVE-2009-0641 primarily affects Freebsd. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0641?

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-2009-0641 published?

CVE-2009-0641 was published on 2009-02-20 and last updated on 2026-06-16.

CVE-2009-0641

CVE-2009-0641 is a critical-severity vulnerability in Freebsd with a CVSS 2.0 base score of 9.3. 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-16.

Key facts

Severity: Critical (CVSS 2.0 base score 9.3)
EPSS exploit prediction: 9% (95th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-16
Affected product: Freebsd
Published: 2009-02-20
Last modified: 2026-06-16

Description

sys_term.c in telnetd in FreeBSD 7.0-RELEASE and other 7.x versions deletes dangerous environment variables with a method that was valid only in older FreeBSD distributions, which might allow remote attackers to execute arbitrary code by passing a crafted environment variable from a telnet client, as demonstrated by an LD_PRELOAD value that references a malicious library.

Frequently asked questions

What is CVE-2009-0641?: sys_term.c in telnetd in FreeBSD 7.0-RELEASE and other 7.x versions deletes dangerous environment variables with a method that was valid only in older FreeBSD distributions, which might allow remote attackers to execute arbitrary code by passing a crafted environment variable from a telnet client, as demonstrated by an LD_PRELOAD value that references a malicious library.
How severe is CVE-2009-0641?: CVE-2009-0641 has a CVSS 2.0 base score of 9.3, rated critical severity.
Is CVE-2009-0641 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0641?: CVE-2009-0641 primarily affects Freebsd. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0641?: 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-2009-0641 published?: CVE-2009-0641 was published on 2009-02-20 and last updated on 2026-06-16.

References

Affected products (8)

cpe:2.3:o:freebsd:freebsd:7.0:*:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:7.0:beta_4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:7.0:current:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:7.0-release:*:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:7.0_beta4:*:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:7.0_releng:*:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:7.1:*:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:7.1:rc1:*:*:*:*:*:*

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