[GO-2023-1987] Large RSA keys can cause high CPU usage in crypto/tls

Severity Medium

Affected Packages 3

Fixed Packages 3

CVEs 1

Extremely large RSA keys in certificate chains can cause a client/server to
expend significant CPU time verifying signatures.

With fix, the size of RSA keys transmitted during handshakes is restricted to <=
8192 bits.

Based on a survey of publicly trusted RSA keys, there are currently only three
certificates in circulation with keys larger than this, and all three appear to
be test certificates that are not actively deployed. It is possible there are
larger keys in use in private PKIs, but we target the web PKI, so causing
breakage here in the interests of increasing the default safety of users of
crypto/tls seems reasonable.

Package	Affected Version
pkg:golang/crypto/tls	>= 1.20.6, < 1.19.12
pkg:golang/crypto/tls	>= 1.20.6, < 1.20.7
pkg:golang/crypto/tls	>= 1.20.6, < 1.21.0-rc.4

Package	Fixed Version
pkg:golang/crypto/tls	= 1.19.12
pkg:golang/crypto/tls	= 1.20.7
pkg:golang/crypto/tls	= 1.21.0-rc.4

ID

GO-2023-1987

Severity

medium

Severity from

CVE-2023-29409

URL

https://pkg.go.dev/vuln/GO-2023-1987

Published

2023-08-01T21:49:21
(13 months ago)

Modified

2024-07-17T19:54:18
(2 months ago)

Other Advisories

Type	Package URL	Namespace	Name / Product	Version
Fixed	pkg:golang/crypto/tls	crypto	tls	= 1.19.12
Affected	pkg:golang/crypto/tls	crypto	tls	>= 1.20.6 < 1.19.12
Fixed	pkg:golang/crypto/tls	crypto	tls	= 1.20.7
Affected	pkg:golang/crypto/tls	crypto	tls	>= 1.20.6 < 1.20.7
Fixed	pkg:golang/crypto/tls	crypto	tls	= 1.21.0-rc.4
Affected	pkg:golang/crypto/tls	crypto	tls	>= 1.20.6 < 1.21.0-rc.4

# CVE	Description	CVSS	EPSS	EPSS Trend (30 days)	Affected Products	Weaknesses	Security Advisories	Exploits	PoC	Pubblication Date	Modification Date
# CVE	Description	CVSS	EPSS	EPSS Trend (30 days)	Affected Products	Weaknesses	Security Advisories	PoC	Pubblication Date	Modification Date