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NVD / CVE Program· CNA mitre

CVE-2009-1755: Off-by-one error in the packet_read_query_section function in packet.c in nsd 3.2.1, and process_query_section in query.c in nsd 2.3.7, allo

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 3.1% (FIRST EPSS); higher than 87.8% of all records.
  • No special conditions are required; it is repeatable.
  • Fixed version: nsd (Debian:12) 2.3.7-3; nsd (Debian:4.0) 2.3.6-1+etch1; nsd (Debian:5.0) 2.3.7-1.1+lenny1.

Low priority for now. Upgrade to nsd (Debian:12) 2.3.7-3; nsd (Debian:4.0) 2.3.6-1+etch1; nsd (Debian:5.0) 2.3.7-1.1+lenny1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Off-by-one error in the packet_read_query_section function in packet.c in nsd 3.2.1, and process_query_section in query.c in nsd 2.3.7, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors that trigger a buffer overflow.

MediumCVSS 5.0 · v2.0—No exploit Fix available
Published
May 22, 2009
Updated
Jun 16, 2026
EPSS
3.1% · 87th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
20 / 40 · 5.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 3.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
nlnetlabsnsd

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • nlnetlabs nsd2.0.0
  • nlnetlabs nsd2.0.1
  • nlnetlabs nsd2.0.2
  • nlnetlabs nsd2.1.0
  • nlnetlabs nsd2.1.1
  • nlnetlabs nsd2.1.2
  • nlnetlabs nsd2.1.3
  • nlnetlabs nsd2.1.4
  • nlnetlabs nsd2.1.5
  • nlnetlabs nsd2.3.7
  • nlnetlabs nsd3.2.1

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12nsdbefore 2.3.7-32.3.7-3
Debian:4.0nsdbefore 2.3.6-1+etch12.3.6-1+etch1
Debian:5.0nsdbefore 2.3.7-1.1+lenny12.3.7-1.1+lenny1
Debian:5.0nsd3before 3.0.7-3.lenny23.0.7-3.lenny2

Same product

nlnetlabs: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-12245Denial of DNS over TLS service by any DoT client
    34Monitor
  • CVE-2026-12244Heap overflow and crash with crafted SVCB RR
    34Monitor
  • CVE-2026-19538Bypass of BLOCKED ACL items on proxy protocol port over TCP or TLS
    32Monitor

Published before and after this one in the same product

  • Later →CVE-2012-2978Jul 27, 2012 · query.c in NSD 3.0.x through 3.0.8, 3.1.x through 3.1.1, and 3.2.x before 3.2.12 allows remote attackers to cause a denial of service (NULL
    23Monitor
  • Later →CVE-2016-6173Feb 9, 2017 · NSD before 4.1.11 allows remote DNS master servers to cause a denial of service (/tmp disk consumption and slave server crash) via a zone tr
    31Monitor
  • Later →CVE-2026-12246Jun 25, 2026 · Out of bounds stack write with crafted APL RR
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:nsd2.3.7-3 · Debian:12Package registry (OSV)
debian:nsd33.0.7-3.lenny2 · Debian:5.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
P · the service can be disrupted
Attack complexity
Low
Confidentiality impact
None
Integrity impact
None
Availability impact
P

Weakness class (CWE)

CWE-189 · Numeric Errors

CVSS vector

AV:N/AC:L/Au:N/C:N/I:N/A:P

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records