Vulnerability record · CVE-2014-3506 · published 13 August 2014
CVE-2014-3506: OpenSSL DTLS handshake memory exhaustion denial of service
OOpenssl · Openssl
OpenSSL's DTLS implementation in d1_both.c fails to properly validate length values in crafted handshake messages, causing memory allocations proportional to attacker-supplied large lengths. A remote unauthenticated attacker can exhaust process memory and cause a denial of service. The flaw affects OpenSSL 0.9.8 before 0.9.8zb, 1.0.0 before 1.0.0n, and 1.0.1 before 1.0.1i.
Description
d1_both.c in the DTLS implementation in OpenSSL 0.9.8 before 0.9.8zb, 1.0.0 before 1.0.0n, and 1.0.1 before 1.0.1i allows remote attackers to cause a denial of service (memory consumption) via crafted DTLS handshake messages that trigger memory allocations corresponding to large length values.
AV:N/AC:L/Au:N/C:N/I:N/A:P
Automated analysis
high priorityRemote unauthenticated memory-exhaustion DoS with a high EPSS percentile, though no KEV listing or confirmed public exploit in the record.
What it is
OpenSSL's DTLS implementation in d1_both.c fails to properly validate length values in crafted handshake messages, causing memory allocations proportional to attacker-supplied large lengths. A remote unauthenticated attacker can exhaust process memory and cause a denial of service. The flaw affects OpenSSL 0.9.8 before 0.9.8zb, 1.0.0 before 1.0.0n, and 1.0.1 before 1.0.1i.
Impact
An attacker can force excessive memory allocation in the affected OpenSSL process, leading to memory exhaustion and denial of service. There is no confidentiality or integrity impact per the CVSS vector.
Attack surface
Reachable over the network via DTLS handshake messages; the CVSS vector AV:N/AC:L/Au:N indicates no authentication is required and no user interaction is needed. Any service exposing DTLS (for example, DTLS-based TLS endpoints) is potentially reachable.
Exploitation
Not listed in CISA KEV and no ransomware associations are documented. EPSS is 0.46124 (98.755th percentile), indicating a high modeled likelihood of exploitation activity, but the record contains no reference tags confirming public exploit code.
What to do
- Upgrade OpenSSL to 0.9.8zb, 1.0.0n, 1.0.1i or later, or apply the vendor patch for your distribution.
- Apply the referenced vendor errata (Red Hat RHSA-2014-1256/RHSA-2014-1297, Oracle ELSA-2014-1052/1053, IBM AIX, NetBSD, openSUSE) where OpenSSL is bundled.
- If DTLS is not required, disable DTLS listeners and restrict UDP exposure to trusted networks.
- Monitor and cap memory usage for processes that terminate DTLS, and restart them on abnormal growth.
- Inventory all OpenSSL deployments, including embedded and third-party components, to confirm patched versions.
Detection
- Monitor DTLS endpoints for abnormal memory growth or process restarts that correlate with inbound handshake traffic.
- Inspect network traffic for DTLS handshake messages carrying unusually large length values or repeated handshake retransmissions.
- Alert on OpenSSL process crashes or OOM-killer events on hosts that terminate DTLS.
- Track patch status of OpenSSL versions against the fixed releases 0.9.8zb, 1.0.0n and 1.0.1i.
This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
Track CVE-2014-3506 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2014-3506), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.
