CVE-2026-45685

Description

### Summary Malformed MongoDB wire messages can trigger uncaught panics in the MongoDB TCP parser, allowing a remote unauthenticated attacker to crash the telemetry agent and cause a denial of service. The parser operates on raw attacker-controlled network payloads before the input is fully validated, so a single crafted message can terminate telemetry collection for the affected process or node. ### Details MongoDB parsing support was introduced by commit `2070f568a` (`Add Initial support for mongodb`), so the explicit released version minimum affected is `v0.1.0`. There are two related panic conditions in released `go.opentelemetry.io/obi` versions: - In `v0.1.0` through `v0.3.0`, `parseOpMessage` reads OP_MSG flag bits from `buf[msgHeaderSize:msgHeaderSize+int32Size]` without first ensuring the buffer is at least `msgHeaderSize + int32Size` bytes long. A truncated OP_MSG packet can therefore trigger a slice-bounds panic before the parser returns an error. - In `v0.1.0` through `v0.3.0`, `parseSections` consumes the section type byte and then reads the document-sequence length from `buf[offSet:offSet+int32Size]` without re-validating that enough bytes remain after the type byte. A malformed document-sequence section can therefore trigger another slice-bounds panic. - In `v0.1.0` through `v0.8.0`, `parseFirstField` assumes the collection name for collection-scoped commands is always a string and performs an unchecked type assertion on `field.Value`. A malformed BSON document can therefore trigger a runtime panic with `interface conversion` instead of returning a parse error. The bounds-check panic was fixed by commit `3aa58cdaaa97fbb72f8ef4c3609ae425aacaf8bb` (`Fix MongoDB client panic`), which first appears in release `v0.4.0`. The unchecked BSON type assertion is still present in `v0.8.0`. Because this code runs while decoding attacker-controlled MongoDB traffic, the failure mode is process termination rather than graceful rejection of invalid input. In deployments where the telemetry agent monitors traffic from untrusted or partially trusted clients, a single malformed packet can terminate collection until the agent is restarted. Affected code paths are in `pkg/ebpf/common/mongo_detect_transform.go` and correspond to `parseOpMessage`, `parseSections`, and `parseFirstField`. ### PoC The following reproductions are fully self-contained. They create a temporary test file inside an affected checkout and then run `go test` against the real parser code in the repository. 1. Reproduce the `v0.1.0` through `v0.3.0` bounds-check panics: ```bash git clone https://github.com/open-telemetry/opentelemetry-ebpf-instrumentation.git obi-poc cd obi-poc git checkout v0.3.0 cat > pkg/ebpf/common/mongo_security_poc_test.go <<'EOF' package ebpfcommon import "testing" func TestSecurityPoCParseOpMessageShortPanics(t *testing.T) { parseOpMessage(make([]byte, 16), 0, false, nil) } func TestSecurityPoCParseSectionsShortDocSequencePanics(t *testing.T) { parseSections([]byte{byte(sectionTypeDocumentSequence), 0x01, 0x02, 0x03}) } EOF go test ./pkg/ebpf/common -run 'TestSecurityPoCParseOpMessageShortPanics|TestSecurityPoCParseSectionsShortDocSequencePanics' -count=1 ``` Expected result: - `TestSecurityPoCParseOpMessageShortPanics` panics with a message similar to `slice bounds out of range [:20] with capacity 16` - `TestSecurityPoCParseSectionsShortDocSequencePanics` panics with a message similar to `slice bounds out of range [:5] with capacity 4` 1. Reproduce the `v0.1.0` through `v0.8.0` unchecked BSON type-assertion panic: ```bash git clone https://github.com/open-telemetry/opentelemetry-ebpf-instrumentation.git obi-poc cd obi-poc git checkout v0.8.0 cat > pkg/ebpf/common/mongo_security_poc_test.go <<'EOF' package ebpfcommon import ( "testing" "go.mongodb.org/mongo-driver/v2/bson" ) func TestSecurityPoCParseFirstFieldTypeAssertionPanics(t *testing.T) { parseFirstField(bson.E{Key: commFind, Value: int32(123)}) } EOF go test ./pkg/ebpf/common -run TestSecurityPoCParseFirstFieldTypeAssertionPanics -count=1 ``` Expected result: panic with a message similar to `interface conversion: interface {} is int32, not string`. ### Impact This is a remote denial-of-service vulnerability in the MongoDB protocol parser. Any deployment that enables MongoDB parsing and processes attacker-controlled or malformed MongoDB traffic is impacted. Successful exploitation lets an unauthenticated attacker crash the telemetry agent by sending a crafted OP_MSG packet or malformed BSON document, causing loss of observability until the process is restarted.