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.
CVE-2017-16944
Score elevated to 8.4 because EPSS predicts 63% probability of exploitation within the next 30 days (top 0.9% of all CVEs). NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.
- High exploitation likelihood — EPSS 63%
- Public exploit code is available (Exploit-DB (verified), epss top5pct, epss high, public exploit)
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 8.4(high)
- EG Risk
- 68(Track)EG Risk 68/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity84% × 45%Exploitation65% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 63%
- EPSS %ILE
- 99%
- KEV
- Not listed
Published
November 25, 2017
Last Modified
June 17, 2026
References (18)
- cve@mitrehttp://openwall.com/lists/oss-security/2017/11/25/1
- cve@mitrehttp://openwall.com/lists/oss-security/2017/11/25/2
- cve@mitrehttp://openwall.com/lists/oss-security/2017/11/25/3
- cve@mitrehttp://www.openwall.com/lists/oss-security/2021/05/04/7
- cve@mitrehttp://www.securitytracker.com/id/1039873
- cve@mitrehttps://bugs.exim.org/show_bug.cgi?id=2201
- cve@mitrehttps://lists.exim.org/lurker/message/20171125.034842.d1d75cac.en.html
- cve@mitrehttps://www.debian.org/security/2017/dsa-4053
- cve@mitrehttps://www.exploit-db.com/exploits/43184/
- af854a3a-2127-422b-91ae-364da2661108http://openwall.com/lists/oss-security/2017/11/25/1
- af854a3a-2127-422b-91ae-364da2661108http://openwall.com/lists/oss-security/2017/11/25/2
- af854a3a-2127-422b-91ae-364da2661108http://openwall.com/lists/oss-security/2017/11/25/3
- af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/05/04/7
- af854a3a-2127-422b-91ae-364da2661108http://www.securitytracker.com/id/1039873
- af854a3a-2127-422b-91ae-364da2661108https://bugs.exim.org/show_bug.cgi?id=2201
Patch Availability(1)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | exim4-daemon-light (4.88-5ubuntu1.3) @ zesty | 2026-05-22 | ubuntu |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(5 across 5 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| exim4 | — | 4.89-13 | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| exim4 | — | 4.89-13 | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| exim4 | — | 4.89-13 | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| exim4 | — | 4.89-13 | — |
Debian:9(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| exim4 | 4.89-2, 4.89-2+deb9u1, 4.89-2+deb9u1~bpo8+1 | 4.89-2+deb9u2 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(1)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
Data Freshness Timeline
(refreshed 6× in last 7d / 22× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-20 22:50 UTCEPSS rescore
- 2026-08-19 16:59 UTCEPSS rescore
- 2026-08-18 13:43 UTCEPSS rescore
- 2026-08-17 13:42 UTCEPSS rescore
- 2026-08-16 02:10 UTCEPSS rescore
- 2026-08-15 01:26 UTCEPSS rescore
- 2026-08-13 21:56 UTCEPSS rescore
- 2026-08-13 15:51 UTCOSV refresh
- 2026-08-09 13:42 UTCEPSS rescore
- 2026-08-08 16:32 UTCEPSS rescore
- 2026-08-07 16:22 UTCEPSS rescore
- 2026-08-05 19:12 UTCEPSS rescore
- 2026-08-01 04:11 UTCEPSS rescore
- 2026-07-30 16:24 UTCEPSS rescore
- 2026-07-30 01:26 UTCEPSS rescore
- 2026-07-28 21:51 UTCOSV refresh
- 2026-07-28 15:32 UTCEPSS rescore
- 2026-07-26 14:51 UTCEPSS rescore
- 2026-07-25 14:13 UTCEPSS rescore
- 2026-07-23 14:15 UTCEPSS rescore
- 2026-07-23 01:28 UTCEG score recompute▲ 0.90
- 2026-07-22 22:07 UTCEG score recompute
- 2026-07-22 14:04 UTCEPSS rescore
- 2026-07-20 17:04 UTCEPSS rescore
- 2026-07-20 17:04 UTCEPSS rescore
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- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-16 16:59 UTCEPSS rescore
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- 2026-07-15 16:54 UTCEPSS rescore
- 2026-07-15 16:54 UTCEPSS rescore
- 2026-07-13 22:26 UTCEPSS rescore
- 2026-07-13 06:09 UTCEPSS rescore
- 2026-07-12 05:43 UTCEPSS rescore
- 2026-07-11 14:41 UTCOSV refresh
- 2026-07-11 08:24 UTCEPSS rescore
- 2026-07-09 19:06 UTCEPSS rescore
- 2026-07-04 06:28 UTCEPSS rescore
- 2026-07-01 15:02 UTCEPSS rescore
- 2026-07-01 15:02 UTCEPSS rescore
- 2026-06-28 04:53 UTCEPSS rescore
- 2026-06-27 03:05 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-24 14:02 UTCEPSS rescore
- 2026-06-23 21:30 UTCEPSS rescore
- 2026-06-22 21:05 UTCOSV refresh
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-15 17:45 UTCEPSS rescore
- 2026-06-13 22:57 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-11 13:57 UTCEPSS rescore
- 2026-06-10 22:15 UTCEPSS rescore
- 2026-06-08 14:14 UTCEPSS rescore
- 2026-06-07 15:22 UTCEPSS rescore
- 2026-06-07 15:22 UTCEPSS rescore
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-05 22:44 UTCEPSS rescore
- 2026-06-05 12:27 UTCOSV refresh
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-01 13:49 UTCEPSS rescore
- 2026-06-01 13:49 UTCEPSS rescore
- 2026-05-31 22:28 UTCEPSS rescore
- 2026-05-31 00:14 UTCEPSS rescore
- 2026-05-29 13:41 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-22 21:15 UTCEPSS rescore
- 2026-05-22 21:15 UTCEPSS rescore
- 2026-05-22 21:15 UTCEPSS rescore
- 2026-05-22 07:42 UTCEG score recompute
- 2026-05-22 07:42 UTCVendor advisory
- 2026-05-22 07:42 UTCGHSA enrichment
- 2026-05-20 22:37 UTCEPSS rescore
- 2026-05-20 22:37 UTCEPSS rescore
- 2026-05-20 04:33 UTCOSV refresh
- 2026-05-18 21:30 UTCEPSS rescore
- 2026-05-18 21:30 UTCEPSS rescore
Publicly available exploits
(1 reference)Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Exploit-DBEDB-43184✓ verifiedFirst seen Nov 27, 2017
Exim 4.89 - 'BDAT' Denial of Service
Open source ↗
Frequently asked(5)
What is CVE-2017-16944?
When was CVE-2017-16944 disclosed?
Is CVE-2017-16944 actively exploited?
What is the CVSS score of CVE-2017-16944?
How do I remediate CVE-2017-16944?
Dependency Blast Radius
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