Vulnerability identifier: #VU45006

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2011-1947

CWE-ID: CWE-399

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Fetchmail
Client/Desktop applications / Office applications

Vendor: fetchmail.berlios.de

Description

The vulnerability allows a remote non-authenticated attacker to perform service disruption.

fetchmail 5.9.9 through 6.3.19 does not properly limit the wait time after issuing a (1) STARTTLS or (2) STLS request, which allows remote servers to cause a denial of service (application hang) by acknowledging the request but not sending additional packets.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Fetchmail: 5.9.9 - 6.3.19

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External links
http://gitorious.org/fetchmail/fetchmail/blobs/legacy_63/fetchmail-SA-2011-01.txt
http://lists.fedoraproject.org/pipermail/package-announce/2011-June/061634.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-June/061672.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-June/061735.html
http://openwall.com/lists/oss-security/2011/05/30/1
http://openwall.com/lists/oss-security/2011/05/31/12
http://openwall.com/lists/oss-security/2011/05/31/17
http://openwall.com/lists/oss-security/2011/06/01/2
http://www.fetchmail.info/fetchmail-SA-2011-01.txt
http://www.mandriva.com/security/advisories?name=MDVSA-2011:107
http://www.securityfocus.com/archive/1/518251/100/0/threaded
http://www.securityfocus.com/bid/48043
http://www.securitytracker.com/id?1025605
http://exchange.xforce.ibmcloud.com/vulnerabilities/67700

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.