CVE-2024-3296VulnerabilityPublished 4 Apr 2024Updated 25 Feb 2026

CVE-2024-3296: rust-openssl · Timing Side Channel

Affects rust-opensslSource CVE Database V5

Not known to be exploited · CVSS 5.9 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

5.9Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 35% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-25.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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
crates.iorust-openssl`pkg:cargo/rust-openssl`Other threats	Affected =3.2.0	Fixed in–

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AI-suggested

To mitigate CVE-2024-3296, organizations should: 1) Upgrade rust-openssl to a version that addresses this timing side-channel vulnerability once available, or apply vendor patches promptly. 2) Disable the use of legacy PKCS#1 v1.5 RSA encryption padding in favor of more secure padding schemes such as RSA-OAEP, which are not vulnerable to Bleichenbacher-style attacks. 3) Implement network-level protections to limit the rate and volume of decryption requests, reducing the feasibility of timing attacks. 4) Employ constant-time cryptographic operations and side-channel resistant implementations where possible. 5) Monitor cryptographic libraries and dependencies for updates and advisories related to this vulnerability. 6) Conduct security assessments and penetration testing to detect potential exploitation attempts. 7) For critical systems, consider additional layers of encryption or tokenization to minimize exposure of plaintext data. These steps go beyond generic advice by focusing on disabling vulnerable padding modes, controlling attack surface exposure, and enforcing cryptographic best practices.

Description

A timing-based side-channel flaw exists in the rust-openssl package, which could be sufficient to recover a plaintext across a network in a Bleichenbacher-style attack. To achieve successful decryption, an attacker would have to be able to send a large number of trial messages for decryption. The vulnerability affects the legacy PKCS#1v1.5 RSA encryption padding mode.

Impact

The primary impact of CVE-2024-3296 is the potential compromise of confidentiality for encrypted communications relying on the vulnerable rust-openssl implementation of PKCS#1 v1.5 RSA padding. Attackers capable of sending numerous decryption requests and measuring timing can recover plaintext data, which may include sensitive information such as cryptographic keys, credentials, or private messages. This can lead to data breaches, unauthorized access, and undermining of trust in secure communication channels. The vulnerability does not affect integrity or availability directly but can facilitate further attacks if plaintext data is critical. Organizations using rust-openssl 3.2.0 in network-facing applications or services that accept RSA-encrypted data are at risk. The high attack complexity and requirement for many queries reduce the likelihood of widespread exploitation, but targeted attacks against high-value targets remain plausible. The absence of known exploits suggests limited current threat but does not preclude future exploitation. The impact is global, affecting any entity using the vulnerable library and legacy RSA padding, including enterprises, cloud providers, and software vendors.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Feb 2026, 09:24 UTC

Technical details

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