Critical severity · published May 6, 2021
CVE-2020-28024
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…
9.8
CVSS
4.2%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)4.2% · higher than 91% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EX
Exim · Exim
4.00 before 4.94.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-28024
CVE.org
https://www.cve.org/CVERecord?id=CVE-2020-28024
Third Party Advisory
https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28024-UNGET.txt
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