CVE-2022-4304 — Timing Oracle in RSA Decryption
A timing based side channel exists in the OpenSSL RSA Decryption implementation which could be sufficient to recover a plaintext across a network in a Bleichenbacher style attack. To achieve a successful decryption an attacker would have to be able to send a very large number of trial messages for decryption. The vulnerability affects all RSA padding modes: PKCS#1 v1.5, RSA-OEAP and RSASVE. For example, in a TLS connection, RSA is commonly used by a client to send an encrypted pre-master secret to the server. An attacker that had observed a genuine connection between a client and a server could use this flaw to send trial messages to the server and record the time taken to process them. After a sufficiently large number of messages the attacker could recover the pre-master secret used for the original connection and thus be able to decrypt the application data sent over that connection.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 16.2% (30-day exploitation probability)+15
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Rust Openssl-src: fixed in version 111.25.0 — github.com (GitHub Security Advisories)
- Rust Openssl-src: fixed in version 300.0.12 — github.com (GitHub Security Advisories)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Openssl Openssl, Stormshield Endpoint Security, Stormshield Sslvpn…).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 97% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (info disclosure), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Openssl | Openssl | ≥ 1.0.2 and < 1.0.2zg≥ 1.1.1 and < 1.1.1t≥ 3.0.0 and < 3.0.8 | Vulnerable | NIST National Vulnerability Database |
| Openssl | Openssl | ≥ 3.0.0 and < 3.0.8≥ 1.1.1 and < 1.1.1t≥ 1.0.2 and < 1.0.2zg | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Stormshield | Endpoint Security | < 7.2.40 | Vulnerable | NIST National Vulnerability Database |
| Stormshield | Sslvpn | < 3.2.1 | Vulnerable | NIST National Vulnerability Database |
| StormShield | StormShield Network Security | ≥ 2.7.0 and < 2.7.11≥ 2.8.0 and < 3.7.34≥ 3.8.0 and < 3.11.22≥ 4.0.0 and < 4.3.16≥ 4.4.0 and < 4.6.3 | Vulnerable | NIST National Vulnerability Database |
| Rust | Openssl-src | < 111.25.0≥ 300.0.0 and < 300.0.12 | Vulnerable | GitHub Security Advisories |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.9 | CVSS 3.1 | Medium | 2.2 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 5.9 | CVSS 3.1 | Medium | 2.2 | 3.6 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 5.9 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
| 5.9 | CVSS 3.1 | Medium | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for anomalous data read/export volumes and access to sensitive records.
Timeline
What happened to this CVE, newest first.
- 2026
- Fix documented
- Affected products added · rust/openssl-src
- Affected products added · openssl/openssl
- SSVC assessment updated
- Record published
- Affected products added · openssl/openssl, stormshield/endpoint security, stormshield/sslvpn, stormshield/stormshield network security
- CVSS changed · 5.9
- Source status changed · → Modified
- Record created in this database
- 2023
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
18 on the record
- www.openssl.org/news/secadv/20230207.txt
- cert-portal.siemens.com/productcert/html/ssa-879734.html
- nvd.nist.gov/vuln/detail/CVE-2022-4304
- cert-portal.siemens.com/productcert/html/ssa-943925.html
- cert-portal.siemens.com/productcert/html/ssa-794697.html
- cert-portal.siemens.com/productcert/html/ssa-264814.html
- rustsec.org/advisories/RUSTSEC-2023-0007.html
- psirt.global.sonicwall.com/vuln-detail/SNWLID-2023-0003
- github.com/advisories/GHSA-p52g-cm5j-mjv4
- cert-portal.siemens.com/productcert/html/ssa-561322.html
- cert-portal.siemens.com/productcert/html/ssa-556635.html
- cert-portal.siemens.com/productcert/html/ssa-337522.html
- cert-portal.siemens.com/productcert/html/ssa-398330.html
- cert-portal.siemens.com/productcert/html/ssa-769027.html
- cert-portal.siemens.com/productcert/html/ssa-625862.html
- security.gentoo.org/glsa/202402-08
- cert-portal.siemens.com/productcert/html/ssa-203374.html
- cert-portal.siemens.com/productcert/html/ssa-699386.html
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-84782 DTLS Retransmits Handshake Messages From a Stale Buffer Offset 16d
- High CVE-2026-84784 QUIC: Unbounded RETIRE_CONNECTION_ID Backlog 16d
- High CVE-2026-84783 Use-After-Free in X.509 Extension Cache Under Concurrent Use 16d
- Medium CVE-2026-75806 Unauthenticated and Undersized DTLS 1.2 AEAD Record Causes DoS 16d
- Low CVE-2026-77696 Timing Side-Channel in SM2 Signature Generation 16d
- Medium CVE-2026-75805 NULL Pointer Dereference in CMP Client Revocation Response Handling 16d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2022-4304 is "Timing Oracle in RSA Decryption", rated Medium. It affects Openssl (Openssl); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.9 describes technical severity. EPSS 16.20% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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