vulnerability / NVI-00013856 / Revision 1
gix-packetline: reachable panic on empty side-band packet (pre-auth network DoS)
GitHub lists this reviewed advisory for gix-packetline. 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.
6.5 medium
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.
gix-packetline
source listed<= 0.21.4
### Summary `gix-packetline` panics when it receives a side-band packet line that contains only the band-id byte with an empty payload. A malicious Git server - or any remote a victim clones/fetches from - can abort the `gix` client process during a normal fetch. This is a pre-authentication, network-triggered denial of service. ### Details In `gix-packetline/src/lib.rs`, `impl From for TextRef` strips a trailing newline with `d[d.len() - 1]`: https://github.com/GitoxideLabs/gitoxide/blob/eac50e1207e2549b23302c9faf595a420b9919fc/gix-packetline/src/lib.rs#L199 When `d` is empty (an empty side-band payload after the band-id byte is removed), `d.len() - 1` underflows `usize` (to `18446744073709551615`, i.e. `0 - 1`) and the index access panics. The empty side-band line is attacker-supplied and is reached during a normal fetch. (Related: an unchecked `split_at_mut` in `gix-packetline/src/blocking_io/read.rs` is in the same DoS class and worth hardening in the same pass.) ### PoC Confirmed against `gix v0.54.0` (crate `gix-packetline 0.21.4`) and current `main`. 1. Run a minimal malicious git server on `127.0.0.1:9418`. It completes a protocol-v2 handshake (ls-refs, fetch), t
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-2vh6-hw4j-32ww ↗
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.