vulnerability / NVI-00008975 / Revision 1
Rustls: Brotli certificate decompression can allocate an attacker-controlled amount of memory up to 1 GiB before authentication.
GitHub lists this reviewed advisory for rustls, rustls. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
3.7 low
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
rustls
source listed< 0.23.46
### Summary The built-in (but disabled by default) Brotli certificate decoder bounds the output buffer but accepts an input-selected history window. A header of five bytes can specify a 1 GiB window allocation. A peer can abort a process whose allocator cannot satisfy that request. A client must enable Brotli and connect to the peer; a server must enable Brotli and request a client certificate. Neither direction requires a trusted attacker certificate. ### Details rustls calls `BrotliDecompress` which enables Brotli's large-window extension. rustls applies a limit to certificates, but this applies to the decompressed result, and not to any internal allocations the process requires. ### Impact Client applications that enable the `brotli` feature will be vulnerable to malicious servers. Server applications that enable the `brotli` feature and enable client authentication will be vulnerable to malicious clients. Potential for denial of service due to memory exhaustion from peers sending malicious Brotli-encoded certificates, for applications that enable Brotli decompression. ### Acknowledgement Thanks to OpenAI [OutboundDisclosures@openai.com](mailto:OutboundDisclosures@openai.
rustls
source listed>= 0.24.0-dev.1, < 0.24.0-dev.2
### Summary The built-in (but disabled by default) Brotli certificate decoder bounds the output buffer but accepts an input-selected history window. A header of five bytes can specify a 1 GiB window allocation. A peer can abort a process whose allocator cannot satisfy that request. A client must enable Brotli and connect to the peer; a server must enable Brotli and request a client certificate. Neither direction requires a trusted attacker certificate. ### Details rustls calls `BrotliDecompress` which enables Brotli's large-window extension. rustls applies a limit to certificates, but this applies to the decompressed result, and not to any internal allocations the process requires. ### Impact Client applications that enable the `brotli` feature will be vulnerable to malicious servers. Server applications that enable the `brotli` feature and enable client authentication will be vulnerable to malicious clients. Potential for denial of service due to memory exhaustion from peers sending malicious Brotli-encoded certificates, for applications that enable Brotli decompression. ### Acknowledgement Thanks to OpenAI [OutboundDisclosures@openai.com](mailto:OutboundDisclosures@openai.
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-h2v8-394m-p7vv ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.