EUVD-2026-40054
GHSA-qqgj-g5f7-jqhm
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Network-reachable, unauthenticated DTLS epoch-0 handshake path; no privileges or interaction required; only availability impact confirmed, no integrity or confidentiality effect established.
Primary rating from Vendor (eclipse).
CVSS VectorVendor: eclipse
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
1DescriptionCVE.org
Eclipse tinydtls before commit b3efd41ad111a4920f599f51ffa4f5e9f1e72221 contains an out-of-bounds read vulnerability in the check_server_certificate() function that allows unauthenticated attackers to trigger reads beyond valid buffer boundaries by crafting a Certificate handshake message with a specific fragment_length value. Attackers can exploit missing buffer length validation before uint24 reads, memcmp, and memcpy operations during DTLS epoch 0 on both client and server paths to cause denial of service on memory-constrained devices.
AnalysisAI
Out-of-bounds read in Eclipse tinydtls prior to commit b3efd41ad111a4920f599f51ffa4f5e9f1e72221 allows unauthenticated network attackers to crash memory-constrained IoT devices by sending a specially crafted Certificate handshake message during DTLS epoch 0. The vulnerable check_server_certificate() function omits buffer length validation before uint24 reads, memcmp, and memcpy operations, enabling reads beyond valid buffer boundaries on both client and server code paths. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | No authentication is required - the vulnerability is triggered during DTLS epoch 0, the unencrypted pre-authentication handshake phase, before any session credentials are established. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N, score 6.9) reflects a network-reachable, zero-interaction, unauthenticated path with low availability impact and no confidentiality or integrity impact on the vulnerable system. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker with network access to a DTLS-enabled tinydtls endpoint initiates a DTLS handshake during epoch 0 and sends a crafted Certificate handshake message in which the fragment_length field is set to a value exceeding the actual buffer size. The check_server_certificate() function reads the uint24 value and proceeds to memcmp or memcpy operations without validating buffer bounds, triggering an out-of-bounds read that corrupts or reads adjacent memory, causing the memory-constrained target device to crash or become unresponsive. … |
| Remediation | The primary fix is to update Eclipse tinydtls to a version that includes commit b3efd41ad111a4920f599f51ffa4f5e9f1e72221, which adds buffer length validation before the uint24 reads, memcmp, and memcpy operations in check_server_certificate(). … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same weakness CWE-125 – Out-of-bounds Read
View allSame technique Denial Of Service
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External POC / Exploit Code
Leaving vuln.today