Authenticated server crash via omitted Protobuf submessage
Published Mar 7, 2026 · Updated Mar 7, 2026
NULL pointer dereference in Bishop Fox Sliver 1.7.3 and earlier allows remote authenticated users to crash the C2 server. The beaconRegisterHandler unmarshals a signed BeaconRegister message, accepts an omitted Register submessage, and dereferences its nil Uuid pointer. A captured implant supplies the required credentials; mTLS, WireGuard, and DNS lack panic recovery, so one malformed message terminates the process and all active sessions until a manual restart.
Summary
What happened
NULL pointer dereference in Bishop Fox Sliver 1.7.3 and earlier allows remote authenticated users to crash the C2 server. The beaconRegisterHandler unmarshals a signed BeaconRegister message, accepts an omitted Register submessage, and dereferences its nil Uuid pointer. A captured implant supplies the required credentials; mTLS, WireGuard, and DNS lack panic recovery, so one malformed message terminates the process and all active sessions until a manual restart.
The record
- CVE
- CVE-2026-29781
- Published
- Mar 7, 2026
- Updated
- Mar 7, 2026
- Vendor
- Bishop Fox
- Product
- Sliver
- Classifications
- CWE-476, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 7, 2026CVE publishedPublication date reported by the CVE source.
- Mar 7, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=<= 1.7.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- mtls_poc.gofunctional · demonstrated
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Technologies
Your stack
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Your stack
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