Unbounded memory growth with session handling in TLSv1.3 (CVE-2024-2511)
Published Last modified Sources: Siemens ProductCERT, BSI, Ubuntu, CVE.org, Msrc Update Guide, EUVD
What is affected, what to do
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.
Update OpenSSL to version 3.2.2, OpenSSL to version 3.1.6, OpenSSL to version 3.0.14.
- Affected
- OpenSSL
lt 3.2.0..3.2.2 - OpenSSL
lt 3.1.0..3.1.6 - OpenSSL
lt 3.0.0..3.0.14 - OpenSSL
lt 1.1.1..1.1.1y
- OpenSSL
- Fixed in
- OpenSSL
3.2.2 - OpenSSL
3.1.6 - OpenSSL
3.0.14 - OpenSSL
1.1.1y
- OpenSSL
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Metrics
5.9
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
5.9
CVSS v3
Severity Medium on the scale from 0 to 10.
Source: Siemens ProductCERT, BSI, Ubuntu, CVE.org, Msrc Update Guide, EUVD
52.4 %
EPSS score
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Source: FIRST EPSS, percentile 99.0
Show all metrics
- Severity
- Medium
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 112.75 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 5.9 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 5.9
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 52.4 %
- High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 99.0
- Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-1325
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
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.
Source: siemens_advisory, BSI WID Portal, BSI CSAF, Ubuntu Security Notices, cvelistv5, NVD (NIST), Microsoft Security Update Guide, ENISA EUVD
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| OpenSSL | OpenSSL |
|
|
| Atlassian | Bitbucket |
|
|
| Atlassian | Jira |
|
|
| Dell | NetWorker |
|
|
| Dell | PowerProtect Data Domain |
|
|
| HPE | HP-UX OpenSSL Software |
|
|
| IBM | AIX |
|
|
| IBM | App Connect Enterprise |
|
|
| IBM | Cognos Analytics |
|
|
| IBM | DataPower Gateway |
|
|
| IBM | InfoSphere Information Server |
|
|
| IBM | Rational Build Forge |
|
|
| IBM | Rational ClearCase |
|
|
| IBM | Rational ClearQuest |
|
|
| IBM | Spectrum Protect Plus |
|
|
| IBM | SPSS |
|
|
| IBM | VIOS |
|
|
| Insyde | UEFI Firmware |
|
|
| Meinberg | LANTIME |
|
|
| NetApp | ActiveIQ Unified Manager |
|
|
| NetApp | Data ONTAP |
|
|
| Open Source | OpenSSL |
|
|
| Phoenix Contact | FL MGUARD |
|
|
| Phoenix Contact | FL MGUARD 1102 |
|
|
| Phoenix Contact | FL MGUARD 1105 |
|
|
| Red Hat | OpenShift Logging |
|
|
Vendors and products
- Atlassian Atlassian Bitbucket Server
- Atlassian Atlassian Jira
- Dell Dell NetWorker
- Dell Powerprotect Data Domain
- Hewlett Packard Enterprise (HPE) Hp-ux Openssl Software
- IBM IBM AIX
- IBM App Connect Enterprise
- IBM Cognos Analytics
- IBM Datapower Gateway
- IBM IBM InfoSphere Information Server
- IBM Rational Build Forge
- IBM IBM Rational ClearCase
Affected operating systems
| Linux | ubuntu | openssl | focal |
| Linux | ubuntu | openssl | jammy |
| Linux | ubuntu | openssl | noble |
Weakness classes (CWE)
CWE-1325Improperly Controlled Sequential Memory Allocation
Base
The product manages a group of objects or resources and performs a separate memory allocation for each object, but it does not properly limit the total amount of memory that is consumed by all of the combined objects.
Entry at MITRE CWE-1325
References & sources
- openssl.orgOpenSSL Advisoryeuvd, Vendor advisory
- github.com3.2.2 git commiteuvd, Patch
- github.com3.1.6 git commiteuvd, Patch
- github.com3.0.14 git commiteuvd, Patch
- github.openssl.org1.1.1y git commiteuvd, Patch
- openwall.comlists/oss-security/2024/04/08/5x_transferred
- security.netapp.comadvisory/ntap-20240503-0013x_transferred
- lists.debian.orgdebian-lts-announce/2024/11/msg00000.html
- lists.debian.orgdebian-lts-announce/2024/10/msg00033.html
- Siemens ProductCERTproductcert/html/ssa-398330.html
- Siemens ProductCERTproductcert/html/ssa-265688.html
- Siemens ProductCERTproductcert/html/ssa-354112.html
- Siemens ProductCERTproductcert/html/ssa-915275.html
- Siemens ProductCERTproductcert/html/ssa-769027.html
- Siemens ProductCERTproductcert/html/ssa-613116.html
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedopenssl.org
New references:- https://github.com/openssl/openssl/commit/7e4d731b1c07201ad9374c1cd9ac5263bdf35bce
- https://github.com/openssl/openssl/commit/b52867a9f618bb955bed2a3ce3db4d4f97ed8e5d
- https://github.com/openssl/openssl/commit/e9d7083e241670332e0443da0f0d4ffb52829f08
- https://github.openssl.org/openssl/extended-releases/commit/5f8d25770ae6437db119dfc951e207271a326640
and 1 more reference
Show 10 original changes
Individual changes of this event as published by NVD Type Action Before After Reference added —https://github.com/openssl/openssl/commit/7e4d731b1c07201ad9374c1cd9ac5263bdf35bceReference added —https://github.com/openssl/openssl/commit/b52867a9f618bb955bed2a3ce3db4d4f97ed8e5dReference added —https://github.com/openssl/openssl/commit/e9d7083e241670332e0443da0f0d4ffb52829f08Reference added —https://github.openssl.org/openssl/extended-releases/commit/5f8d25770ae6437db119dfc951e207271a326640Reference added —https://www.openssl.org/news/secadv/20240408.txtReference removed https://github.com/openssl/openssl/commit/7e4d731b1c07201ad9374c1cd9ac5263bdf35bce—Reference removed https://github.com/openssl/openssl/commit/b52867a9f618bb955bed2a3ce3db4d4f97ed8e5d—Reference removed https://github.com/openssl/openssl/commit/e9d7083e241670332e0443da0f0d4ffb52829f08—Reference removed https://github.openssl.org/openssl/extended-releases/commit/5f8d25770ae6437db119dfc951e207271a326640—Reference removed https://www.openssl.org/news/secadv/20240408.txt—Source identifier: openssl-security@openssl.org
Record modifiedCVE Program
New references:- http://www.openwall.com/lists/oss-security/2024/04/08/5
- https://github.com/openssl/openssl/commit/7e4d731b1c07201ad9374c1cd9ac5263bdf35bce
- https://github.com/openssl/openssl/commit/b52867a9f618bb955bed2a3ce3db4d4f97ed8e5d
- https://github.com/openssl/openssl/commit/e9d7083e241670332e0443da0f0d4ffb52829f08
and 5 more references
Show 18 original changes
Individual changes of this event as published by NVD Type Action Before After Reference added —http://www.openwall.com/lists/oss-security/2024/04/08/5Reference added —https://github.com/openssl/openssl/commit/7e4d731b1c07201ad9374c1cd9ac5263bdf35bceReference added —https://github.com/openssl/openssl/commit/b52867a9f618bb955bed2a3ce3db4d4f97ed8e5dReference added —https://github.com/openssl/openssl/commit/e9d7083e241670332e0443da0f0d4ffb52829f08Reference added —https://github.openssl.org/openssl/extended-releases/commit/5f8d25770ae6437db119dfc951e207271a326640Reference added —https://lists.debian.org/debian-lts-announce/2024/10/msg00033.htmlReference added —https://lists.debian.org/debian-lts-announce/2024/11/msg00000.htmlReference added —https://security.netapp.com/advisory/ntap-20240503-0013/Reference added —https://www.openssl.org/news/secadv/20240408.txtReference removed http://www.openwall.com/lists/oss-security/2024/04/08/5—Reference removed https://github.com/openssl/openssl/commit/7e4d731b1c07201ad9374c1cd9ac5263bdf35bce—Reference removed https://github.com/openssl/openssl/commit/b52867a9f618bb955bed2a3ce3db4d4f97ed8e5d—Reference removed https://github.com/openssl/openssl/commit/e9d7083e241670332e0443da0f0d4ffb52829f08—Reference removed https://github.openssl.org/openssl/extended-releases/commit/5f8d25770ae6437db119dfc951e207271a326640—Reference removed https://lists.debian.org/debian-lts-announce/2024/10/msg00033.html—Reference removed https://lists.debian.org/debian-lts-announce/2024/11/msg00000.html—Reference removed https://security.netapp.com/advisory/ntap-20240503-0013/—Reference removed https://www.openssl.org/news/secadv/20240408.txt—Source identifier: af854a3a-2127-422b-91ae-364da2661108
Record modifiedSiemens ADP
Show 13 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2024/2xxx/CVE-2024-2511.json">CVE-2024-2511</a>Reference added —https://cert-portal.siemens.com/productcert/html/ssa-265688.htmlReference added —https://cert-portal.siemens.com/productcert/html/ssa-354112.htmlReference added —https://cert-portal.siemens.com/productcert/html/ssa-398330.htmlReference added —https://cert-portal.siemens.com/productcert/html/ssa-613116.htmlReference added —https://cert-portal.siemens.com/productcert/html/ssa-769027.htmlReference added —https://cert-portal.siemens.com/productcert/html/ssa-915275.htmlReference removed https://cert-portal.siemens.com/productcert/html/ssa-265688.html—Reference removed https://cert-portal.siemens.com/productcert/html/ssa-354112.html—Reference removed https://cert-portal.siemens.com/productcert/html/ssa-398330.html—Reference removed https://cert-portal.siemens.com/productcert/html/ssa-613116.html—Reference removed https://cert-portal.siemens.com/productcert/html/ssa-769027.html—Reference removed https://cert-portal.siemens.com/productcert/html/ssa-915275.html—Source identifier: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
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<a href="https://intel.neosec.eu/en/cve/CVE-2024-2511"><img src="https://intel.neosec.eu/badge/cve/CVE-2024-2511.svg?lang=en" alt="CVE-2024-2511 – NEOSEC Intel" height="20"></a>