CVE-2018-6789 KEV EXPLOIT
9.8
CRITICAL · CVSS 3.1 · EPSS 82.1% (pctl 100)
Patch first
On CISA KEV — known exploited in the wild, due 2022-05-03.
Description
An issue was discovered in the base64d function in the SMTP listener in Exim before 4.90.1. By sending a handcrafted message, a buffer overflow may happen. This can be used to execute code remotely.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 82.14% — more likely to be exploited than 100% of all CVEs |
| Weakness | CWE-120 |
| On CISA KEV | yes — remediate by 2022-05-03 |
| Public exploit | yes |
| Published | 2018-02-08 |
| Last modified | 2026-06-17 |
CISA KEV
| Name | Exim Buffer Overflow Vulnerability |
|---|---|
| Added | 2021-11-03 |
| Due | 2022-05-03 |
| Vendor / product | Exim / Exim |
| Ransomware use | known |
Affected (3)
| Vendor | Product |
|---|---|
| canonical | ubuntu linux |
| debian | debian linux |
| exim | exim |
Public exploits
| Source | Title | Date |
|---|---|---|
| exploit-db | exim 4.90 - Remote Code Execution | 2018-10-24 |
| exploit-db | Exim < 4.90.1 - 'base64d' Remote Code Execution | 2018-05-02 |
References
- http://openwall.com/lists/oss-security/2018/02/10/2
- http://packetstormsecurity.com/files/162959/Exim-base64d-Buffer-Overflow.html
- http://www.openwall.com/lists/oss-security/2018/02/07/2
- http://www.securityfocus.com/bid/103049
- http://www.securitytracker.com/id/1040461
- https://devco.re/blog/2018/03/06/exim-off-by-one-RCE-exploiting-CVE-2018-6789-en/
- https://exim.org/static/doc/security/CVE-2018-6789.txt
- https://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1
- https://lists.debian.org/debian-lts-announce/2018/02/msg00009.html
- https://usn.ubuntu.com/3565-1/
- https://www.debian.org/security/2018/dsa-4110
- https://www.exploit-db.com/exploits/44571/
- https://www.exploit-db.com/exploits/45671/
- http://openwall.com/lists/oss-security/2018/02/10/2
- http://packetstormsecurity.com/files/162959/Exim-base64d-Buffer-Overflow.html
- http://www.openwall.com/lists/oss-security/2018/02/07/2
- http://www.securityfocus.com/bid/103049
- http://www.securitytracker.com/id/1040461
- https://devco.re/blog/2018/03/06/exim-off-by-one-RCE-exploiting-CVE-2018-6789-en/
- https://exim.org/static/doc/security/CVE-2018-6789.txt
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