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CVE Record

CVE-2024-2511: Unbounded memory growth with session handling in TLSv1.3

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.

MediumCVSS 5.9Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2024-2511 can let a remote client drive memory growth on specific OpenSSL TLS servers until service availability is affected. It is configuration-dependent: TLSv1.3 servers using the non-default SSL_OP_NO_TICKET option are the key concern. Clients, OpenSSL 1.0.2, and listed FIPS modules are not affected.

Executive priority

Treat as a targeted availability risk, not a broad compromise risk. Prioritize externally reachable TLS services, customer-facing platforms, and vendor-managed appliances where downtime matters. Remediation should fit normal patch cycles unless exposure matches the vulnerable configuration on critical systems.

Technical view

In certain TLSv1.3 server configurations, OpenSSL session cache state can become incorrect and fail to flush as it fills. The cache may grow without bound, causing denial of service. The issue is tied to SSL_OP_NO_TICKET, except where early_data and default anti-replay protection are configured.

Likely exposure

Exposure is most likely on internet-facing or high-traffic TLS servers using affected OpenSSL branches with TLSv1.3 and SSL_OP_NO_TICKET. Default configurations may not be exposed. Products bundling OpenSSL, including vendor appliances and Linux distributions, require vendor-specific confirmation.

Exploitation context

The source bundle does not show CISA KEV listing or confirmed active exploitation. The vulnerability is remotely reachable but marked high attack complexity because it depends on specific server configuration and session-cache behavior. Accidental triggering in normal operation is also possible.

Researcher notes

Key constraints are server-side TLSv1.3, non-default SSL_OP_NO_TICKET, and session cache flushing failure. Do not assume all OpenSSL deployments are vulnerable. The available evidence names fixed commits and releases but does not establish exploitation in the wild.

Mitigation direction

  • Upgrade to fixed OpenSSL releases or vendor packages when available.
  • Review TLSv1.3 servers for SSL_OP_NO_TICKET usage.
  • Check whether early_data and default anti-replay protection change exposure.
  • Track vendor advisories for bundled OpenSSL products.
  • Monitor TLS services for abnormal memory growth until remediated.

Validation and detection

  • Inventory OpenSSL versions on TLS servers and appliances.
  • Identify services that support TLSv1.3.
  • Check application or server code for SSL_OP_NO_TICKET configuration.
  • Confirm deployed packages include the relevant vendor fix.
  • Review memory telemetry for affected TLS front ends.
Prepared
Confidence
high
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-1325: Exact CWE lookup

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cve · low confidence lookup

CVE-2024-2511 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.9 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
3ADP providers
15Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.9CVSS 3.1MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H2.23.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.9Medium
CVSS 3.1 vector shape for CVE-2024-2511Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc
CVECVE Program Container
siemens-SADPADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
OpenSSLOpenSSL3.2.0, 3.1.0, 3.0.0, 1.1.1unaffected
Weakness

CWE details

CWE-1325

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-1325 · source CWE mapping

Improperly Controlled Sequential Memory Allocation

Improperly Controlled Sequential Memory Allocation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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