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Weekly Signal
Live intelligence Updated 20 Aug 2026 · 01:51 UTC

Canonical, Debian, Exim +1 more · Ubuntu Linux, Debian Linux, Exim +1 more

CVE-2010-4344

Exim Heap-Based Buffer Overflow Vulnerability

Recommended action

Validate affected assets and exposure now, then remediate on an accelerated schedule. Debian Security advisory Dsa 2131

View response plan
CVSS9.8
EPSS71.9%
KEVYes
ExploitationConfirmed exploitation
RemediationExplicit patch identified ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 71.9%; technical severity is CVSS 9.8.

Heap-based buffer overflow in the string_vformat function in string.c in Exim before 4.70 allows remote attackers to execute arbitrary code via an SMTP session that includes two MAIL commands in conjunction with a large message containing crafted headers, leading to improper rejection logging.

Who should care

  • Teams operating Ubuntu Linux, Debian Linux, Exim +1 more
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether Ubuntu Linux, Debian Linux, Exim +1 more is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Debian Security advisory Dsa 2131
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Treatment intelligence

Remediation intelligence

Not yet verified

Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.

Verification noteAutomated link verification has not completed for this guidance yet.

Patch

Advisory

Required Action

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-119
Affected versions
Canonical Ubuntu Linux (Version 6.06 | Version 8.04 | Version 9.10); Debian Debian Linux (Version 5.0); Exim Exim (End Excluding 4.70); Opensuse Opensuse (Version 11.1 | Version 11.2 | Version 11.3)
Fixed versions
Exim Exim (Fixed from 4.70)
Published
14 December 2010
Attack vector
Network
Privileges required
None
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 71.9%
  4. Signal calculated at 82

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.