Exim up to 4.80 src/dkim.c dkim_exim_query_dns_txt memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k0.00

A vulnerability has been found in Exim up to 4.80 (Mail Server Software) and classified as very critical. Affected by this vulnerability is the function dkim_exim_query_dns_txt of the file src/dkim.c. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Heap-based buffer overflow in the dkim_exim_query_dns_txt function in dkim.c in Exim 4.70 through 4.80, when DKIM support is enabled and acl_smtp_connect and acl_smtp_rcpt are not set to "warn control = dkim_disable_verify," allows remote attackers to execute arbitrary code via an email from a malicious DNS server.

The weakness was disclosed 10/26/2012 as 20121026.080330.74b9147b as not defined posting (Website). The advisory is shared at lists.exim.org. The public release has been coordinated in cooperation with the project team. This vulnerability is known as CVE-2012-5671 since 10/24/2012. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/18/2021).

The vulnerability scanner Nessus provides a plugin with the ID 73621 (Atmail Webmail < 6.6.2 Exim Buffer Overflow), which helps to determine the existence of the flaw in a target environment. It is assigned to the family CGI abuses. The commercial vulnerability scanner Qualys is able to test this issue with plugin 167117 (OpenSuSE Security Update for exim (openSUSE-SU-2014:0983-1)).

Upgrading to version 4.80.1 eliminates this vulnerability. The upgrade is hosted for download at ftp.exim.org. A possible mitigation has been published immediately after the disclosure of the vulnerability. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 12652.

The vulnerability is also documented in the databases at X-Force (79615) and Tenable (73621). The entries 13422 and 57462 are pretty similar.

Productinfo

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Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
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CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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NVD Base Score: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 73621
Nessus Name: Atmail Webmail < 6.6.2 Exim Buffer Overflow
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍

OpenVAS ID: 72537
OpenVAS Name: Debian Security Advisory DSA 2566-1 (exim4)
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: 🔍

Upgrade: Exim 4.80.1
TippingPoint: 🔍

McAfee IPS: 🔍
McAfee IPS Version: 🔍

ISS Proventia IPS: 🔍
Fortigate IPS: 🔍

Timelineinfo

10/24/2012 🔍
10/26/2012 +2 days 🔍
10/26/2012 +0 days 🔍
10/26/2012 +0 days 🔍
10/26/2012 +0 days 🔍
10/26/2012 +0 days 🔍
10/29/2012 +3 days 🔍
10/31/2012 +2 days 🔍
10/31/2012 +0 days 🔍
04/18/2014 +534 days 🔍
04/18/2021 +2557 days 🔍

Sourcesinfo

Advisory: 20121026.080330.74b9147b
Status: Not defined
Coordinated: 🔍

CVE: CVE-2012-5671 (🔍)
OVAL: 🔍

X-Force: 79615
Vulnerability Center: 36897 - Exim 4.70-4.80 Remote Arbitrary Code Execution due to Improper Processing of a DNS Record, High
SecurityFocus: 56285 - Exim DKIM DNS Decoding CVE-2012-5671 Remote Buffer Overflow Vulnerability
Secunia: 51098 - Exim DKIM DNS Decoding Buffer Overflow Vulnerability, Highly Critical
OSVDB: 86616

See also: 🔍

Entryinfo

Created: 10/29/2012 11:26
Updated: 04/18/2021 16:34
Changes: 10/29/2012 11:26 (86), 04/20/2017 13:51 (3), 04/18/2021 16:34 (2)
Complete: 🔍
Committer: olku

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