CVE-2011-0520

The compress_add_dlabel_points function in dns/Compress.c in MaraDNS 1.4.03, 1.4.05, and probably other versions allows remote attackers to cause a denial of service (segmentation fault) and possibly execute arbitrary code via a long DNS hostname with a large number of labels, which triggers a heap-based buffer overflow.

Published: 2011-01-28 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2011-0520 is rated Moderate Risk (60.9/100): CVSS High severity, with high exploitation likelihood (EPSS 5.17%, 91th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize 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-2011-0520

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 2026-06-15 6.25% 5.17% -1.08%
2 2026-03-02 6.84% 6.25% -0.59%
3 2025-07-30 — 6.84% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2011-0520

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2011-0520

OS Trackers for CVE-2011-0520

vendor priority summary link
debian not yet assigned CVE-2011-0520 not yet assigned priority: Debian including 1 source packages (maradns), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2011-0520
gentoo high CVE-2011-0520: 1 GLSA(s) (201111-06), 1 atom(s) (net-dns/maradns); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2011-0520
ubuntu medium CVE-2011-0520 medium priority: Ubuntu including 1 source packages (maradns), 21 status rows across 21 suites (artful, bionic, dapper, hardy, karmic, lucid, maverick, natty, oneiric, precise, quantal, raring, saucy, trusty, upstream, utopic, vivid, wily, xenial, yakkety, zesty): ignored 17, not-affected 2, DNE 1, released 1. https://ubuntu.com/security/CVE-2011-0520

Affected software / configurations for CVE-2011-0520

Vendor Product Version Raw CPE
maradns maradns 1.4.03 cpe:2.3:a:maradns:maradns:1.4.03:*:*:*:*:*:*:*
maradns maradns 1.4.05 cpe:2.3:a:maradns:maradns:1.4.05:*:*:*:*:*:*:*

References for CVE-2011-0520

cvelogic Threat Intelligence