CVE-2023-45287: Before Go 1.20, the RSA based key exchange methods in crypto/tls may exhibit a timing side channel
Vulnerability summary
CVE-2023-45287 is a high (CVSS 7.5) Observable Discrepancy vulnerability in go standard library crypto/tls. EPSS estimates a 1.25% chance of exploitation in the next 30 days, higher than 69.4% of scored vulnerabilities.
Severe, CVSS 7.5 (NVD); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 11 · Related 13Timeline
- 05-12-2023PublishedVulnerability first disclosed.
- 13-02-2025Last modifiedVulnerability information updated.
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.
CVSS metrics
6 scores · 6 sources · 1 version- OSV · Red hatEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · WolfiEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · ChainguardEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
1.25%
Chance of exploitation in the next 30 days
Percentile
69%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.25% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard10 products
- katib-earlystopping< 0.19.0-r31
- katib-suggestion-goptuna-compatAll versions (No fix recorded)
- katib-suggestion-hyperband< 0.19.0-r31
- katib-suggestion-hyperopt< 0.19.0-r40 | < 0.19.0-r31
- katib-suggestion-nas-darts< 0.19.0-r31
Wolfi10 products
- katib-earlystopping< 0.19.0-r31
- katib-suggestion-goptuna-compatAll versions (No fix recorded)
- katib-suggestion-hyperband< 0.19.0-r31
- katib-suggestion-hyperopt< 0.19.0-r40 | < 0.19.0-r31
- katib-suggestion-nas-darts< 0.19.0-r31
Redhat7 products
- containernetworking-plugins< 1:1.2.0-3.el9_2
- containernetworking-plugins-debuginfo< 1:1.2.0-3.el9_2
- containernetworking-plugins-debugsource< 1:1.2.0-3.el9_2
- skopeo< 2:1.14.3-0.1.el9
- skopeo-debuginfo< 2:1.14.3-0.1.el9
Debian1 product
- golang-1.19All versions (No fix recorded)
Go1 product
- stdlib< 1.20.0
Go standard library1 product
- crypto/tls< 1.20.0
Golang1 product
- go< 1.20.0
Ubuntu1 product
- golang-1.20All versions (No fix recorded)
8 vendors · 32 products
