CVE-2018-6789
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
- In the wild
- CISA lists this as exploited in real attacks. Treat as urgent.
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- 2021-11-03 Exploited in the wildAdded to CISA's Known Exploited Vulnerabilities list
- 2022-05-03 Remediation deadlineCISA's due date for federal agencies to fix it
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: yes, CISA lists it. This puts it above everything that is not.
- Exploit odds: 82.1% in the next 30 days (EPSS).
- Severity: 9.8 CRITICAL (CVSS).
- Fix: a patch or advisory is linked.
- It meets the bar for Drop everything: critical, and exploited or very likely to be.
Details
- Published
- Last modified
- Added to CISA KEV
- 2021-11-03
- Exploit probability
- 82.1% · EPSS, next 30 days
- Weakness
- CWE-120 · Classic buffer overflow
- Record status
- Analyzed
Affected
- Exim < 4.90.1
- Debian Linux 7.0
- Debian Linux 8.0
- Debian Linux 9.0
- Canonical Ubuntu Linux 14.04
- Canonical Ubuntu Linux 16.04
- Canonical Ubuntu Linux 17.10
Attack profile CVSS 3.1 · 9.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2018-6789.md and follow it. Check whether this project is affected by CVE-2018-6789. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://exim.org/static/doc/security/CVE-2018-6789.txt
- https://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1
- https://exim.org/static/doc/security/CVE-2018-6789.txt
- https://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1
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
- 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/