CVE-2023-45287

Before Go 1.20, the RSA based key exchange methods in crypto/tls may exhibit a timing side channel

HIGH
7.5
CVSS Score
Published: December 5, 2023 at 04:18 PM UTC
Updated: June 17, 2026 at 06:28 AM UTC
2 products affected across 2 vendorsGoGo

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Severity
HIGH7.5
Exploit prediction
EPSS 1%

Description

Before Go 1.20, the RSA based TLS key exchanges used the math/big library, which is not constant time. RSA blinding was applied to prevent timing attacks, but analysis shows this may not have been fully effective. In particular it appears as if the removal of PKCS#1 padding may leak timing information, which in turn could be used to recover session key bits. In Go 1.20, the crypto/tls library switched to a fully constant time RSA implementation, which we do not believe exhibits any timing side channels.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.20.0
Affected range stops below 1.20.0, so it looks safe — our inference, not a vendor statement
v < 1.20.0
Affected range stops below 1.20.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-203

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