How severe is CVE-2004-0156?

CVE-2004-0156 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2004-0156 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2004-0156?

CVE-2004-0156 affects Ssmtp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2004-0156?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2004-0156 published?

CVE-2004-0156 was published on 2004-06-01 and last updated on 2026-06-16.

CVE-2004-0156

CVE-2004-0156 is a medium-severity vulnerability in Ssmtp with a CVSS 2.0 base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Ssmtp
Published: 2004-06-01
Last modified: 2026-06-16

Description

Format string vulnerabilities in the (1) die or (2) log_event functions for ssmtp before 2.50.6 allow remote mail relays to cause a denial of service and possibly execute arbitrary code.

Frequently asked questions

What is CVE-2004-0156?: Format string vulnerabilities in the (1) die or (2) log_event functions for ssmtp before 2.50.6 allow remote mail relays to cause a denial of service and possibly execute arbitrary code.
How severe is CVE-2004-0156?: CVE-2004-0156 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2004-0156 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2004-0156?: CVE-2004-0156 affects Ssmtp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2004-0156?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2004-0156 published?: CVE-2004-0156 was published on 2004-06-01 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:ssmtp:ssmtp:*:*:*:*:*:*:*:*

More vulnerabilities in Ssmtp

CVE-2008-3962 — Low (CVSS 2.6): The from_format function in ssmtp.c in ssmtp 2.61 and 2.62, in certain configurations, uses uninitialized memory for…
CVE-2004-0423 — Low (CVSS 2.1): The log_event function in ssmtp 2.50.6 and earlier allows local users to overwrite arbitrary files via a symlink attack…

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