How severe is CVE-1999-0393?

CVE-1999-0393 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-1999-0393 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-0393?

CVE-1999-0393 primarily affects Eric Allman Sendmail. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-1999-0393?

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

When was CVE-1999-0393 published?

CVE-1999-0393 was published on 1999-01-01 and last updated on 2026-06-16.

CVE-1999-0393

CVE-1999-0393 is a medium-severity vulnerability in Eric Allman Sendmail 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: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Eric Allman Sendmail
Published: 1999-01-01
Last modified: 2026-06-16

Description

Remote attackers can cause a denial of service in Sendmail 8.8.x and 8.9.2 by sending messages with a large number of headers.

Frequently asked questions

What is CVE-1999-0393?: Remote attackers can cause a denial of service in Sendmail 8.8.x and 8.9.2 by sending messages with a large number of headers.
How severe is CVE-1999-0393?: CVE-1999-0393 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-1999-0393 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-0393?: CVE-1999-0393 primarily affects Eric Allman Sendmail. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-1999-0393?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-1999-0393 published?: CVE-1999-0393 was published on 1999-01-01 and last updated on 2026-06-16.

References

http://marc.info/?l=bugtraq&m=91694391227372&w=2

Affected products (2)

cpe:2.3:a:eric_allman:sendmail:8.8:*:*:*:*:*:*:*
cpe:2.3:a:eric_allman:sendmail:8.9.2:*:*:*:*:*:*:*

More vulnerabilities in Eric Allman Sendmail

CVE-1999-0047 — Critical (CVSS 10.0): MIME conversion buffer overflow in sendmail versions 8.8.3 and 8.8.4.
CVE-1999-0204 — Critical (CVSS 10.0): Sendmail 8.6.9 allows remote attackers to execute root commands, using ident.
CVE-1999-0206 — Critical (CVSS 10.0): MIME buffer overflow in Sendmail 8.8.0 and 8.8.1 gives root access.
CVE-1999-0203 — Critical (CVSS 10.0): In Sendmail, attackers can gain root privileges via SMTP by specifying an improper "mail from" address and an invalid…
CVE-1999-0095 — Critical (CVSS 10.0): The debug command in Sendmail is enabled, allowing attackers to execute commands as root.
CVE-1999-0163 — High (CVSS 7.2): In older versions of Sendmail, an attacker could use a pipe character to execute root commands.

All CVEs affecting Eric Allman Sendmail →