CVE-2020-28024

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Source
https://nvd.nist.gov/vuln/detail/CVE-2020-28024
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2020-28024.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2020-28024
Downstream
Related
Published
2021-05-06T13:15:09Z
Modified
2025-09-19T12:15:22.358760Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

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.

References

Affected packages

Git / github.com/exim/exim

Affected ranges

Type
GIT
Repo
https://github.com/exim/exim
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
919111edac911ba9c15422eafd7c5bf14d416d26

Affected versions

Other

DEVEL_PDKIM_START
exim-4_50
exim-4_51
exim-4_52
exim-4_53
exim-4_54
exim-4_61
exim-4_62
exim-4_63
exim-4_64
exim-4_65
exim-4_66
exim-4_67
exim-4_68
exim-4_69
exim-4_70
exim-4_70_RC3
exim-4_70_RC4
exim-4_71
exim-4_72
exim-4_72_RC1
exim-4_72_RC2
exim-4_73
exim-4_73_RC0
exim-4_73_RC00
exim-4_73_RC1
exim-4_74
exim-4_74_RC1
exim-4_75
exim-4_75_RC1
exim-4_75_RC2
exim-4_75_RC3
exim-4_76
exim-4_76_RC1
exim-4_76_RC2
exim-4_77
exim-4_77_RC1
exim-4_77_RC2
exim-4_77_RC3
exim-4_77_RC4
exim-4_80
exim-4_80_RC1
exim-4_80_RC2
exim-4_80_RC3
exim-4_80_RC4
exim-4_80_RC5
exim-4_80_RC6
exim-4_80_RC7
exim-4_82
exim-4_82_1
exim-4_82_RC1
exim-4_82_RC2
exim-4_82_RC3
exim-4_82_RC4
exim-4_82_RC5
exim-4_83
exim-4_83_RC1
exim-4_83_RC2
exim-4_83_RC3
exim-4_84
exim-4_84_RC1
exim-4_84_RC2
exim-4_85
exim-4_85_RC1
exim-4_85_RC2
exim-4_85_RC3
exim-4_85_RC4
exim-4_86
exim-4_86_RC1
exim-4_86_RC2
exim-4_86_RC3
exim-4_86_RC4
exim-4_86_RC5
exim-4_87
exim-4_87_RC1
exim-4_87_RC2
exim-4_87_RC3
exim-4_87_RC4
exim-4_87_RC5
exim-4_87_RC6
exim-4_87_RC7
exim-4_88
exim-4_88_RC1
exim-4_88_RC2
exim-4_88_RC3
exim-4_88_RC4
exim-4_88_RC5
exim-4_88_RC6
exim-4_89_RC1
exim-4_89_RC3
exim-4_90
exim-4_90_RC1
exim-4_90_RC2
exim-4_90_RC3
exim-4_90_RC4
exim-4_91
exim-4_91_RC1
exim-4_91_RC2
exim-4_91_RC3
exim-4_91_RC4
exim-4_94_RC0
list_safety_merge_proposal

exim-4.*

exim-4.90devstart
exim-4.92
exim-4.92-RC1
exim-4.92-RC2
exim-4.92-RC3
exim-4.92-RC4
exim-4.92-RC5
exim-4.92-RC6
exim-4.92-jgh
exim-4.93
exim-4.93-RC0
exim-4.93-RC1
exim-4.93-RC2
exim-4.93-RC3
exim-4.93-RC4
exim-4.93-RC5
exim-4.93-RC6
exim-4.93-RC7
exim-4.94
exim-4.94-RC1
exim-4.94-RC2
exim-4.94.1

Database specific 

{
    "vanir_signatures": [
        {
            "deprecated": false,
            "signature_type": "Function",
            "signature_version": "v1",
            "digest": {
                "length": 86.0,
                "function_hash": "85807556721849417698167290800033609961"
            },
            "target": {
                "function": "bdat_ungetc",
                "file": "src/src/smtp_in.c"
            },
            "id": "CVE-2020-28024-a5b97121",
            "source": "https://github.com/exim/exim/commit/919111edac911ba9c15422eafd7c5bf14d416d26"
        },
        {
            "deprecated": false,
            "signature_type": "Line",
            "signature_version": "v1",
            "digest": {
                "threshold": 0.9,
                "line_hashes": [
                    "2970847905863908930961351479348962244",
                    "259127508678304675853565838131490768076",
                    "16856440449629165604374376294870505588",
                    "21031574626938302228709321949938569854",
                    "66694532801356984293692391694813765468",
                    "228435147706632689035739186300622821874",
                    "137018139142916213668559470023354199721",
                    "262955889687131153967951266340364206508",
                    "122233694988885115887188843215612136724",
                    "55546132595750780137850156557040648213",
                    "178043897109541241882122479475000937559",
                    "311496951671523793228361465075141960070"
                ]
            },
            "target": {
                "file": "src/src/smtp_in.c"
            },
            "id": "CVE-2020-28024-f33c15e3",
            "source": "https://github.com/exim/exim/commit/919111edac911ba9c15422eafd7c5bf14d416d26"
        }
    ]
}