CVE-2020-28024
highpriority · track · 40EPSS 0.042 · 91 %ileEURUUSEPSS · scored 2026-10-27
Exim 4 before 4.94.2 allows Buffer Underwrite that may result in unauthenticated remote attackers executing arbitrary commands, because smtp_ungetc was only intended to push back characters, but can actually push back non-character error codes such as EOF.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (20)
Products and version ranges known to be affected.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (9)
External citations — patches, advisories, analysis.
- https://packetstormsecurity.com/files/162475/Gentoo-Linux-Security-Advisory-202105-01.htmlcnnvd
- https://ubuntu.com/security/notices/USN-4934-1?_ga=2.264440204.2023876064.1620270652-2089915127.1616724149Patchcnnvd
- https://vigilance.fr/vulnerability/Exim-multiple-vulnerabilities-35237cnnvd
- https://www.auscert.org.au/bulletins/ESB-2021.1512cnnvd
- https://www.auscert.org.au/bulletins/ESB-2021.1562cnnvd
- https://www.cybersecurity-help.cz/vdb/SB2021050420cnnvd
- https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28024-UNGET.txtcnnvd
- https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28024-UNGET.txtenisa_euvd
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