CVE-2019-16928
Out-of-bounds Write
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than CVE-2019-15846. There is a heap-based buffer overflow in string_vformat in string.c involving a long EHLO command.
Official description from the CVE record, published by mitre. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 3.1 Critical 9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: High
Serious or total effect on the secrecy of data.
Integrity impact: High
Serious or total effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Unchanged | The impact stays within the vulnerable component. |
| Confidentiality impact | High | Serious or total effect on the secrecy of data. |
| Integrity impact | High | Serious or total effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at first.org/cvss.
EPSS
- Score
- 0.41638 (41.6% probability)
- Percentile
- 98.7%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA Known Exploited Vulnerabilities
- Name in the catalog
- Exim Out-of-bounds Write Vulnerability
- Added to the catalog
- Mar 3, 2022
- Federal due date
- Mar 17, 2022
CISA assessment as of Feb 4, 2025
- Exploitation
- Recorded by CISA as active
- Automatable
- yes
- Technical impact
- total
Weakness (CWE)
- CWE-787Out-of-bounds Write
References
- lists.exim.org/lurker/message/20190927.032457.c1044d4c.en.h…
- bugs.exim.org/show_bug.cgi?id=2449
- git.exim.org/exim.git/commit/478effbfd9c3cc5a627fc671d4bf94…
- [oss-security] 20190928 Exim CVE-2019-16928 RCE using a heap-based buffer overflow (openwall.com)mailing-list
- [oss-security] 20190928 Re: Exim CVE-2019-16928 RCE using a heap-based buffer overflow (openwall.com)mailing-list
- [oss-security] 20190928 Re: Exim CVE-2019-16928 RCE using a heap-based buffer overflow (openwall.com)mailing-list
- DSA-4536 (debian.org)vendor-advisory
- USN-4141-1 (usn.ubuntu.com)vendor-advisory
- [oss-security] 20190929 Re: Exim CVE-2019-16928 RCE using a heap-based buffer overflow (openwall.com)mailing-list
- 20190929 [SECURITY] [DSA 4536-1] exim4 security update (seclists.org)mailing-list
- FEDORA-2019-006dfc94cd (lists.fedoraproject.org)vendor-advisory
- FEDORA-2019-e080507ba5 (lists.fedoraproject.org)vendor-advisory
- FEDORA-2019-d778bd4137 (lists.fedoraproject.org)vendor-advisory
- GLSA-202003-47 (security.gentoo.org)vendor-advisory
Timeline
- ID reserved
- Record published
- Added to CISA KEV
- Record last updated
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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:32 UTC. Sources and licenses