Exim Internet Mailer up to 4.43 SPA Authentication spa_base64_to_bits memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k0.00

A vulnerability was found in Exim Internet Mailer up to 4.43 (Mail Server Software) and classified as critical. Affected by this issue is the function spa_base64_to_bits of the component SPA Authentication. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Multiple buffer overflows in Exim before 4.43 may allow attackers to execute arbitrary code via (1) an IPv6 address with more than 8 components, as demonstrated using the -be command line option, which triggers an overflow in the host_aton function, or (2) the -bh command line option or dnsdb PTR lookup, which triggers an overflow in the dns_build_reverse function.

The bug was discovered 01/04/2005. The weakness was shared 01/06/2005 by Philip Hazel with Exim Team (Website). The advisory is available at exim.org. This vulnerability is handled as CVE-2005-0021 since 01/04/2005. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details as well as a public exploit are known.

After 2 weeks, there has been an exploit disclosed. The exploit is available at securiteam.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 1 days. During that time the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 19118 (FreeBSD : exim -- two buffer overflow vulnerabilities (ca9ce879-5ebb-11d9-a01c-0050569f0001)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family FreeBSD Local Security Checks and running in the context l.

Upgrading eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at exim.org. The best possible mitigation is suggested to be upgrading to the latest version. A possible mitigation has been published before and not just after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at X-Force (18763), Tenable (19118) and Exploit-DB (756). The entry 1093 is related to this item.

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CPE 2.3info

CPE 2.2info

CVSSv4info

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

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.6
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

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

Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 19118
Nessus Name: FreeBSD : exim -- two buffer overflow vulnerabilities (ca9ce879-5ebb-11d9-a01c-0050569f0001)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍
Nessus Port: 🔍

OpenVAS ID: 53472
OpenVAS Name: Debian Security Advisory DSA 635-1 (exim)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍
Exploit Delay Time: 🔍

Patch: exim.org

Timelineinfo

01/04/2005 🔍
01/04/2005 +0 days 🔍
01/05/2005 +1 days 🔍
01/06/2005 +1 days 🔍
01/06/2005 +0 days 🔍
01/06/2005 +0 days 🔍
01/10/2005 +4 days 🔍
01/14/2005 +4 days 🔍
01/15/2005 +1 days 🔍
01/15/2005 +0 days 🔍
02/01/2005 +16 days 🔍
05/02/2005 +90 days 🔍
07/13/2005 +72 days 🔍
06/30/2019 +5100 days 🔍

Sourcesinfo

Advisory: exim.org
Researcher: Philip Hazel
Organization: Exim Team
Status: Not defined
Confirmation: 🔍

CVE: CVE-2005-0021 (🔍)
OVAL: 🔍

X-Force: 18763
Vulnerability Center: 6963 - Buffer Overflow in University of Cambridge Exim <= 4.43 via IPv6 Address, High
SecurityFocus: 12185 - Exim Illegal IPv6 Address Buffer Overflow Vulnerability
Secunia: 13713 - Exim Three Vulnerabilities, Moderately Critical
OSVDB: 12946 - Exim -bh Command Line Option dns_build_reverse Function Local Overflow

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 01/10/2005 12:19
Updated: 06/30/2019 20:25
Changes: 01/10/2005 12:19 (96), 06/30/2019 20:25 (5)
Complete: 🔍
Cache ID: 18:2FF:103

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