GHSA-cw3j-28qq-x3xh
Duplicate Advisory: Hono vulnerable to Vary Header Injection leading to potential CORS Bypass
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- —
- No score published
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
- Fix
- None yet
- No fixed version published
Description
Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-q7jf-gf43-6x6p. This link is maintained to preserve external references.
Original Description
Hono before 4.10.2 (fixed in 4.10.3) contains a flaw in its CORS middleware: when the origin is not set to "*", the middleware copies the Vary header from the incoming request into the response. Because Vary is a response header that should be managed by the server, an attacker can supply arbitrary Vary values that are reflected into the response, potentially causing cache key pollution and inconsistent CORS enforcement in environments that rely on shared caches or proxies.
Affected versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| hono | all versions |
No fix yet |
How to fix
No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- Low
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Not defined
- Scope
- X
CVSS 3.1 6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Weakness
CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
The product receives data from an HTTP agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes CR and LF characters before the data is included in outgoing HTTP headers.
How to prevent it
- Implementation: Construct HTTP headers very carefully, avoiding the use of non-validated input data.
- 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. If an input does not strictly conform to specifications, reject it or transform it into something that conforms. 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.
- Implementation: Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
References
Advisories
Other links
Timeline
- Published
- Withdrawn
- Last updated by the source
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-5r4p-p66f-jhc7 Hono: `serveStatic` decodes the request path a second time, leading to bypass of middleware on static paths | Medium | Also affects hono |
| GHSA-hxh3-vqpv-xpqv hono/jsx renders plain strings unescaped in boundary components, leading to XSS | Low | Also affects hono |
| GHSA-gqvv-2mrq-wpjv Hono: Incomplete fix for CVE-2026-39408: `toSSG()` still writes files outside the output directory | Medium | Also affects hono |
| GHSA-g6gw-c38x-mqfc Hono: Unbounded dot-notation nesting in `parseBody()` can cause memory exhaustion | Medium | Also affects hono |
| GHSA-crvj-82cr-hjcx Hono: Query parser reads parameters after the URL fragment, causing cache-key and proxy interpretation differentials | Medium | Also affects hono |
| GHSA-f23p-vx2j-j53r Hono: `memo()` retains SSR output across requests, leading to cross-user data disclosure | Medium | Also affects hono |
| GHSA-79qm-7rj5-m7r9 Hono: Proxy Helper does not remove response headers listed in the `Connection` header | Low | Also affects hono |
| GHSA-54fx-42gc-7vw4 Hono: Algorithmic Complexity DoS in Language Middleware | Medium | Also affects hono |
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