CVE-2024-2511
Unbounded memory growth with session handling in TLSv1.3
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Description
Issue summary: Some non-default TLS server configurations can cause unbounded memory growth when processing TLSv1.3 sessions Impact summary: An attacker may exploit certain server configurations to trigger unbounded memory growth that would lead to a Denial of Service This problem can occur in TLSv1.3 if the non-default SSL_OP_NO_TICKET option is being used (but not if early_data support is also configured and the default anti-replay protection is in use). In this case, under certain conditions, the session cache can get into an incorrect state and it will fail to flush properly as it fills. The session cache will continue to grow in an unbounded manner. A malicious client could deliberately create the scenario for this failure to force a Denial of Service. It may also happen by accident in normal operation. This issue only affects TLS servers supporting TLSv1.3. It does not affect TLS clients. The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 1.0.2 is also not affected by this issue.
Official description from the CVE record, published by openssl. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 3.1 Medium 5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: High
The attack depends on conditions outside the attacker's control, so it takes preparation.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: None
No effect on the secrecy of data.
Integrity impact: None
No effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | High | The attack depends on conditions outside the attacker's control, so it takes preparation. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Unchanged | The impact stays within the vulnerable component. |
| Confidentiality impact | None | No effect on the secrecy of data. |
| Integrity impact | None | No effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
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EPSS
- Score
- 0.59304 (59.3% probability)
- Percentile
- 99.1%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA assessment as of Apr 9, 2024
- Automatable
- no
- Technical impact
- partial
Weakness (CWE)
- CWE-1325Improperly Controlled Sequential Memory Allocation
Affected products
OpenSSL
- affected: 3.2.0 up to before 3.2.2
- affected: 3.1.0 up to before 3.1.6
- affected: 3.0.0 up to before 3.0.14
- affected: 1.1.1 up to before 1.1.1y
References
- OpenSSL Advisory (openssl.org)vendor-advisory
- 3.2.2 git commit (github.com)patch
- 3.1.6 git commit (github.com)patch
- 3.0.14 git commit (github.com)patch
- 1.1.1y git commit (github.openssl.org)patch
- openwall.com/lists/oss-security/2024/04/08/5
- security.netapp.com/advisory/ntap-20240503-0013
- lists.debian.org/debian-lts-announce/2024/11/msg00000.html
- lists.debian.org/debian-lts-announce/2024/10/msg00033.html
Timeline
- ID reserved
- Record published
- Record last updated
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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:52 UTC. Sources and licenses