OpenSSL
CVE-2023-2650
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V2 - Validation and Business Logic Resource allocation limits
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 6.5 (MEDIUM). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. |
| Exploit ScenarioDerived | A remote attacker could exhaust system resources through uncontrolled allocation by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Issue summary: Processing some specially crafted ASN.1 object identifiers or data containing them may be very slow. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Allocation of Resources Without Limits vulnerability could allow attackers to exhaust system resources through uncontrolled allocation.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Set resource limits, implement rate limiting, validate input sizes.
Affects your stack
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Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Allocation of Resources Without Limits (CWE-770), which allows attackers to exhaust system resources through uncontrolled allocation. Issue summary: Processing some specially crafted ASN.1 object identifiers or data containing them may be very slow. Impact summary: Applications that use OBJ_obj2txt() directly, or use any of the OpenSSL subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS with no message size limit may experience notable to very long delays when processing those messages, which may lead to a Denial of Service. An OBJECT IDENTIFIER is composed of a series of numbers - sub-identifiers - most of which have no size limit. OBJ_obj2txt() may be used to translate an ASN.1 OBJECT IDENTIFIER given in DER encoding form (using the OpenSSL type ASN1_OBJECT) to its canonical numeric text form, which are the sub-identifiers of the OBJECT IDENTIFIER in decimal form, separated by periods. When one of the sub-identifiers in the OBJECT IDENTIFIER is very large (these are sizes that are seen as absurdly large, taking up tens or hundreds of KiBs), the translation to a decimal number in text may take a very long time. The time complexity is O(n^2) with 'n' being the size of the sub-identifiers in bytes (*). With OpenSSL 3.0, support to fetch cryptographic algorithms using names / identifiers in string form was introduced. This includes using OBJECT IDENTIFIERs in canonical numeric text form as identifiers for fetching algorithms. Such OBJECT IDENTIFIERs may be received through the ASN.1 structure AlgorithmIdentifier, which is commonly used in multiple protocols to specify what cryptographic algorithm should be used to sign or verify, encrypt or decrypt, or digest passed data. Applications that call OBJ_obj2txt() directly with untrusted data are affected, with any version of OpenSSL. If the use is for the mere purpose of display, the severity is considered low. In OpenSSL 3.0 and newer, this affects the subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS. It also impacts anything that processes X.509 certificates, including simple things like verifying its signature. The impact on TLS is relatively low, because all versions of OpenSSL have a 100KiB limit on the peer's certificate chain. Additionally, this only impacts clients, or servers that have explicitly enabled client authentication. In OpenSSL 1.1.1 and 1.0.2, this only affects displaying diverse objects, such as X.509 certificates. This is assumed to not happen in such a way that it would cause a Denial of Service, so these versions are considered not affected by this issue in such a way that it would be cause for concern, and the severity is therefore considered low. Affected products include: Openssl, Debian Debian Linux.
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Severity by source
AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Issue summary: Processing some specially crafted ASN.1 object identifiers or data containing them may be very slow.
Impact summary: Applications that use OBJ_obj2txt() directly, or use any of the OpenSSL subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS with no message size limit may experience notable to very long delays when processing those messages, which may lead to a Denial of Service.
An OBJECT IDENTIFIER is composed of a series of numbers - sub-identifiers - most of which have no size limit. OBJ_obj2txt() may be used to translate an ASN.1 OBJECT IDENTIFIER given in DER encoding form (using the OpenSSL type ASN1_OBJECT) to its canonical numeric text form, which are the sub-identifiers of the OBJECT IDENTIFIER in decimal form, separated by periods.
When one of the sub-identifiers in the OBJECT IDENTIFIER is very large (these are sizes that are seen as absurdly large, taking up tens or hundreds of KiBs), the translation to a decimal number in text may take a very long time. The time complexity is O(n^2) with 'n' being the size of the sub-identifiers in bytes (*).
With OpenSSL 3.0, support to fetch cryptographic algorithms using names / identifiers in string form was introduced. This includes using OBJECT IDENTIFIERs in canonical numeric text form as identifiers for fetching algorithms.
Such OBJECT IDENTIFIERs may be received through the ASN.1 structure AlgorithmIdentifier, which is commonly used in multiple protocols to specify what cryptographic algorithm should be used to sign or verify, encrypt or decrypt, or digest passed data.
Applications that call OBJ_obj2txt() directly with untrusted data are affected, with any version of OpenSSL. If the use is for the mere purpose of display, the severity is considered low.
In OpenSSL 3.0 and newer, this affects the subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS. It also impacts anything that processes X.509 certificates, including simple things like verifying its signature.
The impact on TLS is relatively low, because all versions of OpenSSL have a 100KiB limit on the peer's certificate chain. Additionally, this only impacts clients, or servers that have explicitly enabled client authentication.
In OpenSSL 1.1.1 and 1.0.2, this only affects displaying diverse objects, such as X.509 certificates. This is assumed to not happen in such a way that it would cause a Denial of Service, so these versions are considered not affected by this issue in such a way that it would be cause for concern, and the severity is therefore considered low.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)NVD
The (1) TLS and (2) DTLS implementations in OpenSSL 1.0.1 before 1.0.1g do not properly handle Heartbeat Extension packe
In order to decrypt SM2 encrypted data an application is expected to call the API function EVP_PKEY_decrypt(). Rated cri
The dtls1_reassemble_fragment function in d1_both.c in OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before 1.0
OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before 1.0.1h does not properly restrict processing of ChangeCiph
The SSLv2 protocol, as used in OpenSSL before 1.0.1s and 1.0.2 before 1.0.2g and other products, requires a server to se
The ssl3_get_key_exchange function in s3_clnt.c in OpenSSL before 0.9.8zd, 1.0.0 before 1.0.0p, and 1.0.1 before 1.0.1k
In addition to the c_rehash shell command injection identified in CVE-2022-1292, further circumstances where the c_rehas
The TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not pro
The SSL protocol 3.0, as used in OpenSSL through 1.0.1i and other products, uses nondeterministic CBC padding, which mak
The AES-NI implementation in OpenSSL before 1.0.1t and 1.0.2 before 1.0.2h does not consider memory allocation during a
The X509_verify_cert function in crypto/x509/x509_vfy.c in OpenSSL 1.0.1n, 1.0.1o, 1.0.2b, and 1.0.2c does not properly
A buffer overrun can be triggered in X.509 certificate verification, specifically in name constraint checking. Rated hig
GitHub PoC
Exploit-DB