CVE-2006-1721

digestmd5.c in the CMU Cyrus Simple Authentication and Security Layer (SASL) library 2.1.18, and possibly other versions before 2.1.21, allows remote unauthenticated attackers to cause a denial of service (segmentation fault) via malformed inputs in DIGEST-MD5 negotiation.

Published: 2006-04-11 Last update: 2026-04-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2006-1721 is rated Moderate Risk (41.5/100): CVSS Low severity, with medium exploitation likelihood (EPSS 3.61%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2006-1721

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-05-05 2.97% 3.61% +0.64%
2 2025-04-26 2.45% 2.97% +0.52%
3 2025-03-30 — 2.45% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2006-1721

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.6 2.0 LOW
AV:N/AC:H/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:H)
Exploitation requires uncommon or highly specific conditions.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 4.9 2.9 [email protected]

Weakness enumeration for CVE-2006-1721

OS Trackers for CVE-2006-1721

vendor priority summary link
debian low CVE-2006-1721 low priority: Debian including 1 source packages (cyrus-sasl2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2006-1721
gentoo normal CVE-2006-1721: 1 GLSA(s) (200604-09), 1 atom(s) (dev-libs/cyrus-sasl); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2006-1721
redhat medium — https://access.redhat.com/security/cve/CVE-2006-1721
ubuntu medium CVE-2006-1721 medium priority: Ubuntu including 2 source packages (cyrus-sasl2, cyrus-sasl2-heimdal), 8 status rows across 4 suites (dapper, edgy, feisty, upstream): DNE 3, released 3, needs-triage 2. https://ubuntu.com/security/CVE-2006-1721

Affected software / configurations for CVE-2006-1721

Vendor Product Version Raw CPE
cyrus sasl 2.1.18 cpe:2.3:a:cyrus:sasl:2.1.18:*:*:*:*:*:*:*
cyrus sasl 2.1.18_r1 cpe:2.3:a:cyrus:sasl:2.1.18_r1:*:*:*:*:*:*:*
cyrus sasl 2.1.18_r2 cpe:2.3:a:cyrus:sasl:2.1.18_r2:*:*:*:*:*:*:*
cyrus sasl 2.1.19 cpe:2.3:a:cyrus:sasl:2.1.19:*:*:*:*:*:*:*
cyrus sasl 2.1.20 cpe:2.3:a:cyrus:sasl:2.1.20:*:*:*:*:*:*:*

References for CVE-2006-1721

URL Tags
ftp://patches.sgi.com/support/free/security/advisories/20070901-01-P.asc
http://asg.web.cmu.edu/archive/message.php?mailbox=archive.cyrus-sasl&msg=7775
http://labs.musecurity.com/advisories/MU-200604-01.txt Patch
http://lists.apple.com/archives/security-announce/2006/Sep/msg00002.html
http://lists.grok.org.uk/pipermail/full-disclosure/2006-April/044992.html
http://secunia.com/advisories/19618 Patch Vendor Advisory
http://secunia.com/advisories/19753 Vendor Advisory
http://secunia.com/advisories/19809 Vendor Advisory
http://secunia.com/advisories/19825 Vendor Advisory
http://secunia.com/advisories/19964 Vendor Advisory
http://secunia.com/advisories/20014 Vendor Advisory
http://secunia.com/advisories/22187 Vendor Advisory
http://secunia.com/advisories/26708 Vendor Advisory
http://secunia.com/advisories/26857 Vendor Advisory
http://secunia.com/advisories/27237 Vendor Advisory
http://secunia.com/advisories/30535 Vendor Advisory
http://securitytracker.com/id?1016960
http://support.avaya.com/elmodocs2/security/ASA-2007-426.htm
http://www.debian.org/security/2006/dsa-1042
http://www.gentoo.org/security/en/glsa/glsa-200604-09.xml
http://www.mandriva.com/security/advisories?name=MDKSA-2006:073
http://www.novell.com/linux/security/advisories/2006_05_05.html
http://www.redhat.com/support/errata/RHSA-2007-0795.html
http://www.redhat.com/support/errata/RHSA-2007-0878.html
http://www.securityfocus.com/archive/1/493080/100/0/threaded
http://www.securityfocus.com/bid/17446 Patch
http://www.trustix.org/errata/2006/0024
http://www.vmware.com/security/advisories/VMSA-2008-0009.html
http://www.vupen.com/english/advisories/2006/1306 Vendor Advisory
http://www.vupen.com/english/advisories/2006/3852 Vendor Advisory
http://www.vupen.com/english/advisories/2008/1744 Vendor Advisory
https://exchange.xforce.ibmcloud.com/vulnerabilities/25738
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9861
https://usn.ubuntu.com/272-1/
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