VulnerabilityPublished 16 May 2024Updated 14 Oct 2024

CVE-2024-4603: OpenSSL · Unchecked Input for Loop Condition

Affects OpenSSLSource GCVE Database

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Not known to be exploited · CVSS 5.3 Medium.

Data as of 6 Nov 2026, 23:23 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CISA-ADP	CVSS 3.1	5.3

EPSS: 1.1% chance of exploitation in 30 days – higher than 66% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 May 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
OpenSSL OpenSSL	Affected 3.0.0 – 3.3.0 4 affected builds	Fixed in–

AI-suggested

Since the vulnerability affects only applications that explicitly call EVP_PKEY_param_check() or EVP_PKEY_public_check() with untrusted input, mitigation involves avoiding the use of these functions on untrusted DSA keys or parameters. Users of the OpenSSL pkey and pkeyparam command line tools should avoid using the -check option on untrusted inputs. Monitor the OpenSSL vendor advisories for official patches or updates addressing this issue.

Description

CVE-2024-4603 is a vulnerability in OpenSSL 3.0 and 3.1 FIPS providers where unchecked input for loop conditions in DSA key parameter checks can cause excessive processing delays. Applications that call EVP_PKEY_param_check() or EVP_PKEY_public_check() with untrusted DSA keys or parameters may be vulnerable to denial of service due to long computation times on very large modulus values. The OpenSSL SSL/TLS implementation itself is not affected. The vulnerability also affects the OpenSSL pkey and pkeyparam command line tools when used with the -check option.

Impact

The impact is a denial of service condition caused by excessive processing delays when checking DSA keys or parameters with very large modulus sizes. This can be exploited if an attacker supplies maliciously crafted keys or parameters to an application that calls EVP_PKEY_param_check() or EVP_PKEY_public_check(). There is no confidentiality or integrity impact reported. The OpenSSL SSL/TLS protocol implementation is not affected, limiting the scope to applications that directly use these checking functions or the affected command line tools.

CWE-606Unchecked Input for Loop Condition (opens in a new tab)
Base weakness
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.
Implementation
Do not use user-controlled data for loop conditions.
Implementation
Perform input validation.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-834Excessive Iteration (opens in a new tab)
Class weakness
The product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 20:52 UTC

WeaknessesCWE-606, CWE-834

Technical details

References

Community reviews

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