CVE-2021-43523

mediumpriority · track · 39EPSS 0.031 · 88 %ileEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
3.07% (88th) EPSS
CVSS 6.8 · medium
Is it mine?
8 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cisa_csaf_ot

EPSS · scored 2026-10-27

In uClibc and uClibc-ng before 1.0.39, incorrect handling of special characters in domain names returned by DNS servers via gethostbyname, getaddrinfo, gethostbyaddr, and getnameinfo can lead to output of wrong hostnames (leading to domain hijacking) or injection into applications (leading to remote code execution, XSS, applications crashes, etc.). In other words, a validation step, which is expected in any stub resolver, does not occur.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

  • FixedAFF660/665cisa_csaf_ot

    Update to upcoming AFF660/665 FW 04.6.01 release when available.

  • MitigationAFF660/665cisa_csaf_ot

    Configure only trusted DNS server(s).

02

cvss

Technical severity, 0–10. One row per scoring source.

9.6
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 6.8–9.6

v2.06.8mediumAV:N/AC:M/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 6.4
v3.19.6criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 6
v3.09.6criticalCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Hsecondary · CISA US
v3.19.6criticalAV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.19.6criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Hsecondary · ENISA EU
v3.19.6criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Hsecondaryexploitability 2.8 · impact 6
v3.18.8highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-79USprimaryCWE-79USCWE-79US
05

affected products (8)

Products and version ranges known to be affected.

06

advisories (1)

Vendor and ecosystem advisories describing this.

  • ICSA-23-234-01Hitachi Energy AFF66x2023-08-22icsa · cisa_csaf_otUS

    Successful exploitation of these vulnerabilities could allow an attacker to compromise availability, integrity, and confidentiality of the targeted devices.

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisa_csaf_otnvdNVDCVE.orgMITRE
published 2021-11-10modified 2026-06-17
10

references (11)

External citations — patches, advisories, analysis.

scry

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