Exim 4.88/4.89 SMTP Daemon receive.c receive_msg use after free

CVSS Meta Temp Score
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CTI Interest Score
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8.4$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in Exim 4.88/4.89. Affected by this issue is the function receive_msg of the file receive.c of the component SMTP Daemon. The manipulation results in use after free. This vulnerability was named CVE-2017-16943. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Exim 4.88/4.89 (Mail Server Software). It has been classified as critical. Affected is the function receive_msg of the file receive.c of the component SMTP Daemon. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The bug was discovered 11/26/2017. The weakness was presented 11/25/2017 (Website). The advisory is shared for download at openwall.com. This vulnerability is traded as CVE-2017-16943 since 11/25/2017. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 104808 (Ubuntu 17.04 / 17.10 : exim4 vulnerability (USN-3493-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 277008 (Fedora Security Update for exim (FEDORA-2017-0032baa7d7)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 2 days after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (104808). See VDB-109969 for similar entry. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.5
VulDB Meta Temp Score: 8.4

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 104808
Nessus Name: Ubuntu 17.04 / 17.10 : exim4 vulnerability (USN-3493-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 860736
OpenVAS Name: SuSE Update for exim openSUSE-SU-2017:3220-1 (exim)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Patch: git.exim.org

Timelineinfo

11/25/2017 🔍
11/25/2017 +0 days 🔍
11/25/2017 +0 days 🔍
11/26/2017 +1 days 🔍
11/26/2017 +0 days 🔍
11/27/2017 +1 days 🔍
11/28/2017 +1 days 🔍
01/16/2023 +1875 days 🔍

Sourcesinfo

Advisory: USN-3493-1
Status: Not defined

CVE: CVE-2017-16943 (🔍)
GCVE (CVE): GCVE-0-2017-16943
GCVE (VulDB): GCVE-100-109968

OVAL: 🔍

SecurityTracker: 1039872

See also: 🔍

Entryinfo

Created: 11/26/2017 16:41
Updated: 01/16/2023 11:30
Changes: 11/26/2017 16:41 (74), 12/10/2019 16:15 (3), 01/25/2021 07:41 (2), 01/16/2023 11:23 (4), 01/16/2023 11:30 (1)
Complete: 🔍
Cache ID: 216::103

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