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Fencer Intel
high 7.5

CVE-2011-0520 json

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…

published 2011-01-28 15 y ago modified 2026-06-16 4 mo ago also EUVD-2011-0540

cvss
7.5
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.2%
EPSS 5.2% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

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.

Patch / fix

  • maradns Debian 11 1.4.03-1.1

debian advisories DEBIAN-CVE-2011-0520

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2011-0520 updated cvss 7.5

MaraDNS: Heap-based buffer overflow by processing long DNS hostname with a large number of labels

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

5.17% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.