Description
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.
Affected products
openssl: openssl; stormshield: endpoint security; stormshield: sslvpn; stormshield: stormshield network security
References10
- www.openssl.org/news/secadv/20230207.txt Vendor Advisory
- www.openssl.org/news/secadv/20230207.txt Vendor Advisory
- security.gentoo.org/glsa/202402-08
- psirt.global.sonicwall.com/vuln-detail/SNWLID-2023-0003
- security.gentoo.org/glsa/202402-08
- cert-portal.siemens.com/productcert/html/ssa-203374.html
- cert-portal.siemens.com/productcert/html/ssa-264814.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-556635.html
Metrics
- CVSS 3.1
-
5.9
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 24% percentile: 98 · as of 6 November 2026
- CWE
- CWE-203
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.