GHSA-5RW4-4665-CVWF
Vulnerability from github – Published: 2026-08-18 20:48 – Updated: 2026-08-18 20:48Froxlor's DomainZones.add API command accepts user-controlled DNS record and type values and later writes them into generated BIND zone files without rejecting line delimiters, tab characters, or zone-file comment delimiters.
The stronger variant is in record. An authenticated customer with DNS-zone permissions can submit a normal A record request where record is:
www\t60\tIN\tA\t6.6.6.6 ;\n@
with type=A and content=127.0.0.1. The current record flow trims/lower-cases/IDNA-encodes the value, but does not reject CR/LF/HTAB or semicolon. The real Froxlor\Dns\DnsEntry::__toString() sink renders it as:
www 60 in a 6.6.6.6 ; @ 18000 IN A 127.0.0.1
BIND accepts the generated zone file:
named-checkzone example.com froxlor_dns_record_injected.zone zone example.com/IN: loaded serial 2026060501 OK
named-compilezone -D confirms both records are parsed as real DNS RRs:
example.com. 18000 IN A 127.0.0.1 www.example.com. 60 IN A 6.6.6.6 zone example.com/IN: loaded serial 2026060501 OK
Affected code in 2.3.7: - lib/Froxlor/Api/Commands/DomainZones.php:92-93 reads record/type from API params. - lib/Froxlor/Api/Commands/DomainZones.php:122-136 trims/lower-cases/IDNA-encodes record without control-character rejection. - lib/Froxlor/Api/Commands/DomainZones.php:157-160 hardens content only. - lib/Froxlor/Api/Commands/DomainZones.php:314-321 and 347-357 store record/type/content into domain_dns_entries. - lib/Froxlor/Dns/Dns.php:297 passes stored values to DnsEntry. - lib/Froxlor/Dns/DnsEntry.php:83 concatenates record/type/content into a zone-file line.
There is also a related type-field variant because type is not allowlisted and domain_dns_entries.type is varchar(10). The value NS\tns.\n@\tA renders one submitted entry as multiple zone-file records.
Impact: authenticated customer with DNS-zone permissions can inject additional BIND resource-record lines into the generated zone file for a domain they can manage in Froxlor, bypassing Froxlor's DNS field-level validation. This is DNS zone integrity loss and possible DNS availability impact inside the caller's manageable zone.
Suggested remediation: allowlist DNS RR types, reject CR/LF/HTAB/control chars/spaces/semicolon in record and type, validate record as a DNS owner name while allowing intended cases such as @, , .label, _service._proto, _dmarc, and DKIM selectors. Add defense-in-depth in DnsEntry or the DNS serializer so CR/LF cannot reach generated zone lines.
Attribution: Yaohui Wang.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 2.3.7"
},
"package": {
"ecosystem": "Packagist",
"name": "froxlor/froxlor"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.3.8"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-54543"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-74"
],
"github_reviewed": true,
"github_reviewed_at": "2026-08-18T20:48:04Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "Froxlor\u0027s DomainZones.add API command accepts user-controlled DNS record and type values and later writes them into generated BIND zone files without rejecting line delimiters, tab characters, or zone-file comment delimiters.\n\nThe stronger variant is in record. An authenticated customer with DNS-zone permissions can submit a normal A record request where record is:\n\nwww\\t60\\tIN\\tA\\t6.6.6.6 ;\\n@\n\nwith type=A and content=127.0.0.1. The current record flow trims/lower-cases/IDNA-encodes the value, but does not reject CR/LF/HTAB or semicolon. The real Froxlor\\Dns\\DnsEntry::__toString() sink renders it as:\n\nwww 60 in a 6.6.6.6 ;\n@ 18000 IN A 127.0.0.1\n\nBIND accepts the generated zone file:\n\nnamed-checkzone example.com froxlor_dns_record_injected.zone\nzone example.com/IN: loaded serial 2026060501\nOK\n\nnamed-compilezone -D confirms both records are parsed as real DNS RRs:\n\nexample.com. 18000 IN A 127.0.0.1\nwww.example.com. 60 IN A 6.6.6.6\nzone example.com/IN: loaded serial 2026060501\nOK\n\nAffected code in 2.3.7:\n- lib/Froxlor/Api/Commands/DomainZones.php:92-93 reads record/type from API params.\n- lib/Froxlor/Api/Commands/DomainZones.php:122-136 trims/lower-cases/IDNA-encodes record without control-character rejection.\n- lib/Froxlor/Api/Commands/DomainZones.php:157-160 hardens content only.\n- lib/Froxlor/Api/Commands/DomainZones.php:314-321 and 347-357 store record/type/content into domain_dns_entries.\n- lib/Froxlor/Dns/Dns.php:297 passes stored values to DnsEntry.\n- lib/Froxlor/Dns/DnsEntry.php:83 concatenates record/type/content into a zone-file line.\n\nThere is also a related type-field variant because type is not allowlisted and domain_dns_entries.type is varchar(10). The value NS\\tns.\\n@\\tA renders one submitted entry as multiple zone-file records.\n\nImpact: authenticated customer with DNS-zone permissions can inject additional BIND resource-record lines into the generated zone file for a domain they can manage in Froxlor, bypassing Froxlor\u0027s DNS field-level validation. This is DNS zone integrity loss and possible DNS availability impact inside the caller\u0027s manageable zone.\n\nSuggested remediation: allowlist DNS RR types, reject CR/LF/HTAB/control chars/spaces/semicolon in record and type, validate record as a DNS owner name while allowing intended cases such as @, *, *.label, _service._proto, _dmarc, and DKIM selectors. Add defense-in-depth in DnsEntry or the DNS serializer so CR/LF cannot reach generated zone lines.\n\nAttribution: Yaohui Wang.",
"id": "GHSA-5rw4-4665-cvwf",
"modified": "2026-08-18T20:48:04Z",
"published": "2026-08-18T20:48:04Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/froxlor/froxlor/security/advisories/GHSA-5rw4-4665-cvwf"
},
{
"type": "WEB",
"url": "https://github.com/froxlor/froxlor/commit/a4f09f09fa71337b6cdff364d0a641d631a0130a"
},
{
"type": "PACKAGE",
"url": "https://github.com/froxlor/froxlor"
},
{
"type": "WEB",
"url": "https://github.com/froxlor/froxlor/releases/tag/2.3.8"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L",
"type": "CVSS_V3"
}
],
"summary": "Froxlor DomainZones.add allows DNS zone-file RR injection via record/type fields"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.