OpenTelemetry-Go: UTF-8 replacement rune bypasses attribute length truncation

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

OpenTelemetry-Go is the Go implementation of OpenTelemetry. From version 1.10.0 until 1.33.0, the sdk/trace/span.go attribute truncation path can fail to enforce AttributeValueLengthLimit for string and string-slice attributes containing the valid Unicode replacement character U+FFFD. safeTruncateValidUTF8 treats the valid replacement rune as invalid UTF-8 and returns the original input, while strings.ToValidUTF8 leaves that valid rune unchanged, so a second safeTruncate attempt can also return the oversized value. An attacker who controls span attribute content can retain values longer than the configured limit, increasing per-span memory use and weakening denial-of-service protection in the instrumented process. This issue is fixed in version 1.33.0.

[ Fixes ]Fixes and patches

• go.opentelemetry.io/otel/sdk 1.33.0Fixed version · GitHub Advisories · go package go.opentelemetry.io/otel/sdk: upgrade to 1.33.0 or later (affected >= 1.10.0, < 1.33.0)

[ Packages ]Affected open-source packages

• go.opentelemetry.io/otel/sdk goAffected >= 1.10.0, < 1.33.0 · fixed in 1.33.0 · GHSA-p9f8-wvj8-2fg8

[ References ]References

• github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-p9f8-wvj8-2fg8x_refsource_CONFIRM
• github.com/open-telemetry/opentelemetry-go/issues/5996x_refsource_MISC
• github.com/open-telemetry/opentelemetry-go/pull/5997x_refsource_MISC
• github.com/open-telemetry/opentelemetry-go/commit/e016a78c9f5b24a1c2beeaad47686c2f2213f49ax_refsource_MISC
• github.com/open-telemetry/opentelemetry-go/releases/tag/sdk/v1.33.0x_refsource_MISC