BlackTreeIndependent security intelligence

Full vulnerability report · 2024

CVE-2023-6237High confidence

Excessive time spent checking invalid RSA public keys

OpenSSL · OpenSSL

5.9MediumCVSS 3.1

Recommended action

Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Mitigation available

Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

2 package states

Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu release	Source package	Vendor state	Fixed version	Evidence
Ubuntu 24.04 LTSnoble · standard archive	`edk2`	Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.	`2024.02-2ubuntu0.6`	Canonical record ↗Source updated 9 Sept 2026
Ubuntu 24.04 LTSnoble · standard archive	`openssl`	Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.	`3.0.10-1ubuntu4`	Canonical record ↗Source updated 9 Sept 2026

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

4 current

SSA-265688 · CSAF 2.0 · revision 13 · interimSiemens ProductCERTSSA-265688: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP V1.1

1 known affected

The vendor explicitly identifies these products as affected by this CVE.

SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Summary: Checking excessively long invalid RSA public keys may take a long time. Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may lead to a Denial of Service. When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time. An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the '-pubin' and '-check' options on untrusted data. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.
Remediation: Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.

SSA-769027 · CSAF 2.0 · revision 1 · interimSiemens ProductCERTSSA-769027: Multiple Vulnerabilities fixed in SCALANCE W700 IEEE 802.11ax devices before V3.0.0

19 known affected

The vendor explicitly identifies these products as affected by this CVE.

SCALANCE WAB762-1 (6GK5762-1AJ00-6AA0)
SCALANCE WAM763-1 (6GK5763-1AL00-7DA0)
SCALANCE WAM763-1 (ME) (6GK5763-1AL00-7DC0)
SCALANCE WAM763-1 (US) (6GK5763-1AL00-7DB0)
SCALANCE WAM766-1 (6GK5766-1GE00-7DA0)
SCALANCE WAM766-1 (ME) (6GK5766-1GE00-7DC0)
SCALANCE WAM766-1 (US) (6GK5766-1GE00-7DB0)
SCALANCE WAM766-1 EEC (6GK5766-1GE00-7TA0)
SCALANCE WAM766-1 EEC (ME) (6GK5766-1GE00-7TC0)
SCALANCE WAM766-1 EEC (US) (6GK5766-1GE00-7TB0)
SCALANCE WUB762-1 (6GK5762-1AJ00-1AA0)
SCALANCE WUB762-1 iFeatures (6GK5762-1AJ00-2AA0)

Summary: Checking excessively long invalid RSA public keys may take a long time. Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may lead to a Denial of Service. When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time. An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the '-pubin' and '-check' options on untrusted data. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.
Remediation: Update to V3.0.0 or later version

SSA-331112 · CSAF 2.0 · revision 1 · interimSiemens ProductCERTSSA-331112: Multiple Vulnerabilities in SINEC NMS Before V3.0 SP1

1 known affected

The vendor explicitly identifies these products as affected by this CVE.

SINEC NMS

Summary: Issue summary: Checking excessively long invalid RSA public keys may take a long time. Impact summary: Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may lead to a Denial of Service. When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time. An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the '-pubin' and '-check' options on untrusted data. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.
Remediation: Update to V3.0 SP1 or later version

SSA-915275 · CSAF 2.0 · revision 1 · interimSiemens ProductCERTSSA-915275: Multiple Vulnerabilities in SINEC INS Before V1.0 SP2 Update 3

1 known affected

The vendor explicitly identifies these products as affected by this CVE.

SINEC INS

Summary: Issue summary: Checking excessively long invalid RSA public keys may take a long time. Impact summary: Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may lead to a Denial of Service. When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time. An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the '-pubin' and '-check' options on untrusted data. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.
Remediation: Update to V1.0 SP2 Update 3 or later version

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current

ENISA EUVD identifier

EUVD-2023-58483

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state: Present in the current official mapping
Known exploitation: Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score: Not supplied in the stored EUVD record
Advisory evidence: No linked advisory details stored yet

Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Mitigation available

What, why and how

Issue summary: Checking excessively long invalid RSA public keys may take a long time. Impact summary: Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may lead to a Denial of Service. When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time. An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the '-pubin' and '-check' options on untrusted data. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.

What

Why

The product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

Why

The product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path: a network path → Unchecked Input for Loop Condition → disrupt the affected service
Attack surface: Network
Privileges required: None: unauthenticated exploitation is possible
User interaction: None
Attack complexity: High: exploitation depends on specific conditions
Security boundary: Unchanged: impact remains within the vulnerable component's security authority
Weakness ? CWE means Common Weakness Enumeration: a standard category for the underlying weakness.: CWE-606 ↗
CWE-606: Unchecked Input for Loop Condition. The product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping.
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land: No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.

NetworkUnauthenticatedDenial of serviceCWE-606

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2023-58483Official EUVD mapping

0 linked advisory records.

Official EUVD record

BSI · German · WID-SEC-W-2026-2912Dell PowerScale OneFS: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Dell PowerScale OneFS ausnutzen, um beliebigen Programmcode auszuführen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, und um Daten zu manipulieren.

Excessive time spent checking invalid RSA public keys

National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

EUVD-2023-58483

What, why and how

Exploit reality and attack path

Official authority intelligence

Patch and workaround

Evidence and provenance

National CERT insights
?
CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.