The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89 allows remote attackers to cause a denial of service (infinite loop and stack exhaustion) via vectors involving BDAT commands and an improper check for a . character signifying the end of the content, related to the bdat_getc function.
Weakness
The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Exim | Exim | 4.88 (including) | 4.88 (including) |
| Exim | Exim | 4.89 (including) | 4.89 (including) |
| Exim4 | Ubuntu | artful | * |
| Exim4 | Ubuntu | devel | * |
| Exim4 | Ubuntu | zesty | * |
References
- http://openwall.com/lists/oss-security/2017/11/25/1
- http://openwall.com/lists/oss-security/2017/11/25/2
- http://openwall.com/lists/oss-security/2017/11/25/3
- http://www.openwall.com/lists/oss-security/2021/05/04/7
- http://www.securitytracker.com/id/1039873
- https://bugs.exim.org/show_bug.cgi?id=2201
- https://lists.exim.org/lurker/message/20171125.034842.d1d75cac.en.html
- https://www.debian.org/security/2017/dsa-4053
- https://www.exploit-db.com/exploits/43184/
- http://openwall.com/lists/oss-security/2017/11/25/1
- http://openwall.com/lists/oss-security/2017/11/25/2
- http://openwall.com/lists/oss-security/2017/11/25/3
- http://www.openwall.com/lists/oss-security/2021/05/04/7
- http://www.securitytracker.com/id/1039873
- https://bugs.exim.org/show_bug.cgi?id=2201
- https://lists.exim.org/lurker/message/20171125.034842.d1d75cac.en.html
- https://www.debian.org/security/2017/dsa-4053
- https://www.exploit-db.com/exploits/43184/