vulnerability / NVI-00016020 / Revision 1
Gogs has Unauthenticated Asymmetric Denial of Service (DoS) via SSH Handshake Stall (File Descriptor Exhaustion)
GitHub lists this reviewed advisory for gogs.io/gogs. 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.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
gogs.io/gogs
source listed< 0.14.3
The Gogs built-in Go SSH server is vulnerable to an unauthenticated, asymmetric Denial of Service (DoS) attack. The application accepts inbound TCP connections and passes them to `golang.org/x/crypto/ssh.NewServerConn` inside a new goroutine without enforcing any read/write deadlines on the underlying `net.Conn`. An unauthenticated attacker can open multiple TCP connections to the SSH port and simply withhold the SSH protocol banner. This forces the server to spawn an unbounded number of goroutines that block indefinitely waiting for socket I/O. This leads to complete File Descriptor (FD) exhaustion, preventing legitimate users from accessing the Git SSH service, and ultimately destabilizing the entire Gogs process (e.g., causing internal log rotation failures). ### Vulnerability Details In `internal/ssh/ssh.go`, the `listen` function contains an accept loop that spawns a goroutine for every incoming connection: ```go for { conn, err := listener.Accept() // ... go func() { // VULNERABILITY: No conn.SetDeadline() is called here sConn, chans, reqs, err := ssh.NewServerConn(conn, config) // ... }() } ``` The `golang.org/x/crypto/ssh` packa
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
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04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-xp79-5mx3-jx52 ↗
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.