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NVD / CVE Program· CNA redhat

CVE-2010-4344: Heap-based buffer overflow in the string_vformat function in string.c in Exim before 4.70 allows remote attackers to execute arbitrary code…

CriticalCVSS 9.8 · v3.1KEVWeaponized Fix available

Noroxi assessment

Priority: Now (action score 91/100)

  • CISA has confirmed exploitation in the wild (Mar 25, 2022). Remediation deadline for US federal agencies: Apr 15, 2022.
  • A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
  • Probability of exploitation in the next 30 days: 71.7% (FIRST EPSS); higher than 99.4% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: exim4 (Debian:12) 4.70-1; exim4 (Debian:5.0) 4.69-9+lenny1; exim (openSUSE:Tumbleweed) 4.86.2-2.2.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Patch today or shut off access. Upgrade to exim4 (Debian:12) 4.70-1; exim4 (Debian:5.0) 4.69-9+lenny1; exim (openSUSE:Tumbleweed) 4.86.2-2.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

Published
Dec 14, 2010
Updated
Jun 16, 2026
EPSS
71.7% · 99th percentile

Report tools

JSON

Action score

91

Now

Patch today or shut off access.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
22 / 30 · 71.7%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Mar 25, 2022. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Apr 15, 2022.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2010-4344

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
eximexim
opensuseopensuse
debiandebian linux
canonicalubuntu linux

Using exim? Add it to your stack and be the first to know about CVEs like this one. (Email server)

Watch new CVEs for exim

When you'll hear from us

  • when a new CVE affecting this product is published
  • when a record in your stack enters KEV or is weaponized

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every Monday

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • exim eximbefore 4.70

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12exim4before 4.70-14.70-1
Debian:5.0exim4before 4.69-9+lenny14.69-9+lenny1
openSUSE:Tumbleweedeximbefore 4.86.2-2.24.86.2-2.2
Red Hat:enterprise_linux:4::aseximbefore 0:4.43-1.RHEL4.5.el4_8.10:4.43-1.RHEL4.5.el4_8.1
Red Hat:enterprise_linux:4::asexim-debuginfobefore 0:4.43-1.RHEL4.5.el4_8.10:4.43-1.RHEL4.5.el4_8.1
Red Hat:enterprise_linux:4::asexim-docbefore 0:4.43-1.RHEL4.5.el4_8.10:4.43-1.RHEL4.5.el4_8.1
Red Hat:enterprise_linux:4::asexim-monbefore 0:4.43-1.RHEL4.5.el4_8.10:4.43-1.RHEL4.5.el4_8.1
Red Hat:enterprise_linux:4::asexim-sabefore 0:4.43-1.RHEL4.5.el4_8.10:4.43-1.RHEL4.5.el4_8.1
Red Hat:enterprise_linux:5::clienteximbefore 0:4.63-5.el5_5.20:4.63-5.el5_5.2
Red Hat:enterprise_linux:5::clientexim-debuginfobefore 0:4.63-5.el5_5.20:4.63-5.el5_5.2
Red Hat:enterprise_linux:5::clientexim-monbefore 0:4.63-5.el5_5.20:4.63-5.el5_5.2
Red Hat:enterprise_linux:5::clientexim-sabefore 0:4.63-5.el5_5.20:4.63-5.el5_5.2
Red Hat:rhel_eus:4.7::aseximbefore 0:4.43-1.RHEL4.5.el4_7.10:4.43-1.RHEL4.5.el4_7.1
Red Hat:rhel_eus:4.7::asexim-debuginfobefore 0:4.43-1.RHEL4.5.el4_7.10:4.43-1.RHEL4.5.el4_7.1
Red Hat:rhel_eus:4.7::asexim-docbefore 0:4.43-1.RHEL4.5.el4_7.10:4.43-1.RHEL4.5.el4_7.1
Red Hat:rhel_eus:4.7::asexim-monbefore 0:4.43-1.RHEL4.5.el4_7.10:4.43-1.RHEL4.5.el4_7.1
Red Hat:rhel_eus:4.7::asexim-sabefore 0:4.43-1.RHEL4.5.el4_7.10:4.43-1.RHEL4.5.el4_7.1
Red Hat:rhel_eus:5.3eximbefore 0:4.63-3.el5_3.10:4.63-3.el5_3.1
Red Hat:rhel_eus:5.3exim-debuginfobefore 0:4.63-3.el5_3.10:4.63-3.el5_3.1
Red Hat:rhel_eus:5.3exim-monbefore 0:4.63-3.el5_3.10:4.63-3.el5_3.1
Red Hat:rhel_eus:5.3exim-sabefore 0:4.63-3.el5_3.10:4.63-3.el5_3.1
Red Hat:rhel_eus:5.4eximbefore 0:4.63-3.el5_4.10:4.63-3.el5_4.1
Red Hat:rhel_eus:5.4exim-debuginfobefore 0:4.63-3.el5_4.10:4.63-3.el5_4.1
Red Hat:rhel_eus:5.4exim-monbefore 0:4.63-3.el5_4.10:4.63-3.el5_4.1

+1

Same product

exim: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-10149A flaw was found in Exim versions 4.87 to 4.91 (inclusive).KEV
    99Now
  • CVE-2018-6789An issue was discovered in the base64d function in the SMTP listener in Exim before 4.90.1.KEV
    94Now
  • CVE-2019-16928Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than CVE-2019-15846.KEV
    81Now

Published before and after this one in the same product

  • ← EarlierCVE-2010-2023Jun 7, 2010 · transports/appendfile.c in Exim before 4.72, when a world-writable sticky-bit mail directory is used, does not verify the st_nlink field of…
    17Monitor
  • ← EarlierCVE-2010-2024Jun 7, 2010 · transports/appendfile.c in Exim before 4.72, when MBX locking is enabled, allows local users to change permissions of arbitrary files or…
    17Monitor
  • Later →CVE-2010-4345Dec 14, 2010 · Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of the exim user account to specify an alternate…KEV
    66This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:exim44.70-1 · Debian:12Package registry (OSV)
opensuse:exim4.86.2-2.2 · openSUSE:TumbleweedPackage registry (OSV)
red hat:exim0:4.43-1.RHEL4.5.el4_7.1 · Red Hat:rhel_eus:4.7::asPackage registry (OSV)
red hat:exim-debuginfo0:4.43-1.RHEL4.5.el4_7.1 · Red Hat:rhel_eus:4.7::asPackage registry (OSV)
red hat:exim-doc0:4.43-1.RHEL4.5.el4_7.1 · Red Hat:rhel_eus:4.7::asPackage registry (OSV)
red hat:exim-mon0:4.43-1.RHEL4.5.el4_7.1 · Red Hat:rhel_eus:4.7::asPackage registry (OSV)
red hat:exim-sa0:4.43-1.RHEL4.5.el4_7.1 · Red Hat:rhel_eus:4.7::asPackage registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Exploit-DB entry ×2

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Exploit-DB entryremote2010-12-11
Exploit-DB entryremote2010-12-16
Metasploit moduleexploit/unix/smtp/exim4_string_formatExim4 string_format Function Heap Buffer Overflowexploit2010-12-07

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Metasploit-8 d
  2. First PoC-4 d
  3. Published
  4. CISA KEV+4118 d
  5. TodayNov 14, 2026+5814 d

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (19 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records