CVE-2017-16943

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-13. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 47%CVSS: 9.8Exploit: Elevated riskExposed: 0

A fix is available — apply it.

The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89 allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free) via vectors involving BDAT commands.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
67(Track*)
EG Risk 67/100SSVC: 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 computed
Severity98% × 45%
Exploitation47% × 40%
Automatability30% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
47%
EPSS %ILE
99%
KEV
Not listed

Published

November 25, 2017

Last Modified

June 17, 2026

Advisory Details (10)

Auto-updated Aug 25, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

[exim-announce] Critical Exim Security Vulnerability: disable chunking

https://lists.exim.org/lurker/message/20171125.034842.d1d75cac.en.html
generic

PoC-Exploit-Mirror/CVE-2017-16944 at master · LetUsFsck/PoC-Exploit-Mirror · GitHub

https://github.com/LetUsFsck/PoC-Exploit-Mirror/tree/master/CVE-2017-16944
generic

exim - Exim Forgejo

https://git.exim.org/exim.git/commitdiff/4e6ae6235c68de243b1c2419027472d7659aa2b4
generic

exim - Exim Forgejo

https://git.exim.org/exim.git/commit/4090d62a4b25782129cc1643596dc2f6e8f63bde
generic

Exim Internet Mailer

https://bugs.exim.org/show_bug.cgi?id=2199
generic
http://www.securitytracker.com/id/1039872
generic🟡 PoC Available

oss-security - 21Nails: Multiple vulnerabilities in Exim

http://www.openwall.com/lists/oss-security/2021/05/04/7
generic🟡 PoC Available

oss-security - Re: RCE in Exim reported

http://openwall.com/lists/oss-security/2017/11/25/3
generic🟡 PoC Available

oss-security - RCE in Exim reported

http://openwall.com/lists/oss-security/2017/11/25/2
generic

oss-security - Re: RCE in Exim reported

http://openwall.com/lists/oss-security/2017/11/25/1

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuexim4-daemon-light (4.88-5ubuntu1.2) @ zesty2026-05-20ubuntu

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)
PackageVulnerable rangeFixed inDependents
exim4—4.89-12—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
exim4—4.89-12—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
exim4—4.89-12—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
exim4—4.89-12—
Debian:9(1)
PackageVulnerable rangeFixed inDependents
exim44.89-2, 4.89-2+deb9u1, 4.89-2+deb9u1~bpo8+14.89-2+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 5× in last 7d / 20× 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.

Showing the most recent 100 of 113 total refreshes for this CVE.

  1. 2026-08-25 13:44 UTCEPSS rescore
  2. 2026-08-24 14:10 UTCEPSS rescore
  3. 2026-08-21 23:44 UTCEPSS rescore
  4. 2026-08-20 22:50 UTCEPSS rescore
  5. 2026-08-19 16:59 UTCEPSS rescore
  6. 2026-08-18 13:43 UTCEPSS rescore
  7. 2026-08-17 13:42 UTCEPSS rescore
  8. 2026-08-16 02:10 UTCEPSS rescore
  9. 2026-08-15 01:26 UTCEPSS rescore
  10. 2026-08-13 21:56 UTCEPSS rescore
  11. 2026-08-10 11:39 UTCOSV refresh
  12. 2026-08-09 13:42 UTCEPSS rescore
  13. 2026-08-07 16:22 UTCEPSS rescore
  14. 2026-08-06 13:42 UTCEPSS rescore
  15. 2026-08-04 15:05 UTCEPSS rescore
  16. 2026-08-02 02:23 UTCEPSS rescore
  17. 2026-08-01 04:11 UTCEPSS rescore
  18. 2026-07-30 16:24 UTCEPSS rescore
  19. 2026-07-30 01:26 UTCEPSS rescore
  20. 2026-07-28 15:32 UTCEPSS rescore
  21. 2026-07-26 14:51 UTCEPSS rescore
  22. 2026-07-25 14:13 UTCEPSS rescore
  23. 2026-07-25 12:11 UTCOSV refresh
  24. 2026-07-23 14:15 UTCEPSS rescore
  25. 2026-07-23 01:28 UTCEG score recompute
Show 75 more
  1. 2026-07-22 22:07 UTCEG score recompute
  2. 2026-07-22 14:04 UTCEPSS rescore
  3. 2026-07-20 17:04 UTCEPSS rescore
  4. 2026-07-20 17:04 UTCEPSS rescore
  5. 2026-07-19 14:28 UTCEPSS rescore
  6. 2026-07-19 14:28 UTCEPSS rescore
  7. 2026-07-18 10:00 UTCEPSS rescore
  8. 2026-07-16 16:59 UTCEPSS rescore
  9. 2026-07-16 16:59 UTCEPSS rescore
  10. 2026-07-15 16:54 UTCEPSS rescore
  11. 2026-07-15 16:54 UTCEPSS rescore
  12. 2026-07-13 22:26 UTCEPSS rescore
  13. 2026-07-13 06:09 UTCEPSS rescore
  14. 2026-07-12 05:43 UTCEPSS rescore
  15. 2026-07-11 08:24 UTCEPSS rescore
  16. 2026-07-09 19:06 UTCEPSS rescore
  17. 2026-07-08 15:10 UTCEPSS rescore
  18. 2026-07-08 06:35 UTCOSV refresh
  19. 2026-07-04 06:28 UTCEPSS rescore
  20. 2026-07-01 15:02 UTCEPSS rescore
  21. 2026-07-01 15:02 UTCEPSS rescore
  22. 2026-06-29 14:03 UTCEPSS rescore
  23. 2026-06-28 04:53 UTCEPSS rescore
  24. 2026-06-25 13:47 UTCEPSS rescore
  25. 2026-06-25 13:47 UTCEPSS rescore
  26. 2026-06-24 14:02 UTCEPSS rescore
  27. 2026-06-23 21:30 UTCEPSS rescore
  28. 2026-06-22 14:23 UTCEPSS rescore
  29. 2026-06-22 14:23 UTCEPSS rescore
  30. 2026-06-21 01:57 UTCEPSS rescore
  31. 2026-06-21 01:57 UTCEPSS rescore
  32. 2026-06-19 18:55 UTCOSV refresh
  33. 2026-06-18 17:50 UTCEPSS rescore
  34. 2026-06-17 17:50 UTCEPSS rescore
  35. 2026-06-16 17:50 UTCEPSS rescore
  36. 2026-06-15 17:45 UTCEPSS rescore
  37. 2026-06-13 22:57 UTCEPSS rescore
  38. 2026-06-12 23:09 UTCEPSS rescore
  39. 2026-06-11 13:57 UTCEPSS rescore
  40. 2026-06-10 22:15 UTCEPSS rescore
  41. 2026-06-08 14:14 UTCEPSS rescore
  42. 2026-06-07 15:22 UTCEPSS rescore
  43. 2026-06-07 15:22 UTCEPSS rescore
  44. 2026-06-05 22:44 UTCEPSS rescore
  45. 2026-06-05 06:08 UTCEPSS rescore
  46. 2026-06-05 06:08 UTCEPSS rescore
  47. 2026-06-04 13:10 UTCEPSS rescore
  48. 2026-06-04 13:10 UTCEPSS rescore
  49. 2026-06-02 20:11 UTCEPSS rescore
  50. 2026-06-02 20:11 UTCEPSS rescore
  51. 2026-06-01 13:49 UTCEPSS rescore
  52. 2026-06-01 13:49 UTCEPSS rescore
  53. 2026-05-31 00:14 UTCEPSS rescore
  54. 2026-05-30 23:53 UTCOSV refresh
  55. 2026-05-29 13:41 UTCEPSS rescore
  56. 2026-05-28 13:42 UTCEPSS rescore
  57. 2026-05-28 13:42 UTCEPSS rescore
  58. 2026-05-27 13:38 UTCEPSS rescore
  59. 2026-05-27 13:38 UTCEPSS rescore
  60. 2026-05-26 13:42 UTCEPSS rescore
  61. 2026-05-26 13:42 UTCEPSS rescore
  62. 2026-05-26 07:17 UTCEPSS rescore
  63. 2026-05-26 07:17 UTCEPSS rescore
  64. 2026-05-22 21:15 UTCEPSS rescore
  65. 2026-05-22 21:15 UTCEPSS rescore
  66. 2026-05-22 21:15 UTCEPSS rescore
  67. 2026-05-20 09:28 UTCVendor advisory
  68. 2026-05-20 09:28 UTCGHSA enrichment
  69. 2026-05-20 05:41 UTCVendor advisory
  70. 2026-05-20 05:41 UTCGHSA enrichment
  71. 2026-05-20 01:54 UTCVendor advisory
  72. 2026-05-20 01:54 UTCGHSA enrichment
  73. 2026-05-19 22:07 UTCVendor advisory
  74. 2026-05-19 22:07 UTCGHSA enrichment
  75. 2026-05-19 18:20 UTCVendor advisory

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2017-16943?
CVE-2017-16943 is a critical vulnerability published on November 25, 2017. The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89 allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free) via vectors involving BDAT commands.
When was CVE-2017-16943 disclosed?
CVE-2017-16943 was first published in the National Vulnerability Database on November 25, 2017, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2017-16943 actively exploited?
CVE-2017-16943 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 47% probability of exploitation in the next 30 days, which ranks it in the top 1.3% of all scored CVEs.
What is the CVSS score of CVE-2017-16943?
CVE-2017-16943 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2017-16943?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2017-16943, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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