GHSA-5rw4-4665-cvwf CVE-2026-54543
Froxlor DomainZones.add allows DNS zone-file RR injection via record/type fields
- Severity
- 5.4 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 0.45%
- Chance of exploitation in the next 30 days. Higher than 38.87% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-20 Improper Input Validation
- CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
- Fix
2.3.8- Upgrade froxlor/froxlor to this version or later
Description
Froxlor'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 versions
Packagist
| Package | Vulnerable | Fixed in |
|---|---|---|
| froxlor/froxlor | < 2.3.8 |
2.3.8 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
froxlor/froxlor Packagist → 2.3.8
- composer
composer require froxlor/froxlor:^2.3.8
Severity breakdown
CVSS 3.1 5.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- Low
Weakness
CWE-20: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How to prevent it
- Architecture and Design: Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses. [REF-1109] [REF-1110] [REF-1111]
- Architecture and Design: Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Architecture and Design, Implementation: Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server. Even though client-side checks provide minimal benefits with respect to server-side security, they are still useful. First, they can support intrusion detection. If the server receives input that should have been rejected by the client, then it may be an indication of an attack. Second, client-side error-checking can provide helpful feedback to the user about the expectations for valid input. Third, there may be a reduction in server-side processing time for accidental input errors, although this is typically a small savings.
- Implementation: When your application combines data from multiple sources, perform the validation after the sources have been combined. The individual data elements may pass the validation step but violate the intended restrictions after they have been combined.
- Implementation: Be especially careful to validate all input when invoking code that crosses language boundaries, such as from an interpreted language to native code. This could create an unexpected interaction between the language boundaries. Ensure that you are not violating any of the expectations of the language with which you are interfacing. For example, even though Java may not be susceptible to buffer overflows, providing a large argument in a call to native code might trigger an overflow.
- Implementation: Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180, CWE-181). Make sure that your application does not inadvertently decode the same input twice (CWE-174). Such errors could be used to bypass allowlist schemes by introducing dangerous inputs after they have been checked. Use libraries such as the OWASP ESAPI Canonicalization control. Consider performing repeated canonicalization until your input does not change any more. This will avoid double-decoding and similar scenarios, but it might inadvertently modify inputs that are allowed to contain properly-encoded dangerous content.
- Implementation: When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.
CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How to prevent it
- Requirements: Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Implementation: Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
References
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-7788-ghfq-c6mh Froxlor: Credential and 2FA secret disclosure via Froxlor API endpoints | Critical | Also affects froxlor/froxlor |
| GHSA-xpr4-8vp6-c87j Froxlor has CSRF Vulnerability in AJAX Endpoint — Missing Cross-Site Request Forgery Protection | Medium | Also affects froxlor/froxlor |
| GHSA-w27m-rmmf-g5w4 Froxlor: Second-Order SQL Injection via `Admins.add` `ipaddress` Parameter Allows Full Database Exfiltration | High | Also affects froxlor/froxlor |
| GHSA-43gm-9rr3-cx7g Froxlor: Stored XSS in DNS TXT Record Content Allows Customer-to-Admin Account Takeover | High | Also affects froxlor/froxlor |
| GHSA-q4rm-m6xh-5pv7 Froxlor customer can create MySQL databases on disallowed servers via Mysqls.add API | Medium | Also affects froxlor/froxlor |
| GHSA-mr9h-45p9-fg8h Froxlor: Authenticated customers can read other customers' allowed sender aliases | Medium | Also affects froxlor/froxlor |
| GHSA-f9rx-7wf7-jr36 Froxlor's API Authentication bypasses 2FA Authentication | High | Also affects froxlor/froxlor |
| GHSA-37m5-m4q3-fc6x Froxlor: BIND Zone File Injection via TXT Record Content | High | Also affects froxlor/froxlor |
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor