Exim Regex use after free
A vulnerability was found in Exim and classified as problematic. This issue affects some unknown processing of the component Regex Handler. The manipulation leads to use after free. The name of the patch is 4e9ed49f8f12eb331b29bd5b6dc3693c520fddc2. It is recommended to apply a patch to fix this issue. The identifier VDB-211073 was assigned to this vulnerability.
- Published
- Oct 17, 2022
- Updated
- Jun 17, 2026
- EPSS
- 4.0% · 90th percentile
- CWE
- CWE-119
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 4.0%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.5
- CNA · VulDB
- 4.6
- 2.9 point gap
CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| exim | exim | cpe:2.3:a:exim:exim |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Using exim? Add it to your stack and be the first to know about CVEs like this one. (Email server)
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- exim eximbefore 4.97
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulDB). Independent of NVD's CPE analysis and usually ahead of it.
unspecified Exim
- n/aaffected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:11 | exim4 | before 4.94.2-7+deb11u4 | 4.94.2-7+deb11u4 |
| Debian:12 | exim4 | before 4.96-4 | 4.96-4 |
| openSUSE:Tumbleweed | exim | before 4.96-3.1 | 4.96-3.1 |
| SUSE:Package Hub 15 SP3 | exim | before 4.94.2-bp153.5.1 | 4.94.2-bp153.5.1 |
| SUSE:Package Hub 15 SP3 | exim | before 4.94.2-bp153.5.1 | 4.94.2-bp153.5.1 |
| SUSE:Package Hub 15 SP4 | exim | before 4.94.2-bp154.2.3.1 | 4.94.2-bp154.2.3.1 |
| SUSE:Package Hub 15 SP4 | exim | before 4.94.2-bp154.2.3.1 | 4.94.2-bp154.2.3.1 |
| SUSE:Package Hub 15 SP5 | exim | before 4.97.1-bp155.5.9.1 | 4.97.1-bp155.5.9.1 |
| SUSE:Package Hub 15 SP5 | exim | before 4.97.1-bp155.5.9.1 | 4.97.1-bp155.5.9.1 |
Same product
exim: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-10149A flaw was found in Exim versions 4.87 to 4.91 (inclusive).KEV99Now
- CVE-2018-6789An issue was discovered in the base64d function in the SMTP listener in Exim before 4.90.1.KEV94Now
- CVE-2010-4344Heap-based buffer overflow in the string_vformat function in string.c in Exim before 4.70 allows remote attackers to execute arbitrary code KEV91Now
- CVE-2019-16928Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than CVE-2019-15846.KEV81Now
- CVE-2010-4345Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of the exim user account to specify an alternate confiKEV66This week
- CVE-2025-26794Exim 4.98 before 4.98.1, when SQLite hints and ETRN serialization are used, allows remote SQL injection.62This 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 / package | Fixed version | Source |
|---|---|---|
| debian:exim4 | 4.96-4 · Debian:12 | Package registry (OSV) |
| opensuse:exim | 4.94.2-bp154.2.3.1 · openSUSE:Leap 15.4 | Package registry (OSV) |
| suse:exim | 4.94.2-bp154.2.3.1 · SUSE:Package Hub 15 SP4 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
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
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Buffer ManipulationCAPEC-123likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- bugs.exim.org/show_bug.cgi?id=2915
- git.exim.org/exim.git/commit/4e9ed49f8f12eb331b29bd5b6dc3693c520fddc2
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EIH4W5R7SHTUEQFWWKB4TUO5YFZX64KV/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TMQ6OCKPNPBPSD37YR4FOWV2R54M2UEP/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WFHLZVHNNO2GWYP5EA4TZQZ5O4GVPARR/
- vuldb.com/?id.211073
- lists.debian.org/debian-lts-announce/2024/10/msg00029.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.