Home/CVE/Exim 4 before 4.94.2 allows Buffer Underwrite that may result in unauthenticated remote attackers executing arbitrary co
CVE

CVE-2020-28024

Exim 4 before 4.94.2 allows Buffer Underwrite that may result in unauthenticated remote attackers executing arbitrary co

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.

CRITICAL · CVSS 9.8 EPSS 0.05505
Schedule remediation
  • EPSS percentile: top 10% of all CVEs by exploitation likelihood
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-787Out-of-bounds Write
▤

Affected Products & Versions

1
exim>= 4.00 and < 4.94.2
▣

Scoring & Timeline

9.8
CRITICAL · CVSS v3.1 · cve@mitre.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD06 May 2021 · 01:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
⚑

Vendor Advisories

6
suse-csafopenSUSE-SU-2024:10746-1
suse-csafopenSUSE-SU-2021:0753-1
suse-csafopenSUSE-SU-2021:0754-1
suse-csafopenSUSE-SU-2021:0677-1
usnUSN-4934-2
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28024-UNGET.txtThird Party Advisory
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