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Medium severity6.8NVD Advisory· Published Oct 2, 2024· Updated Apr 15, 2026

CVE-2024-47616

CVE-2024-47616

Description

Pomerium is an identity and context-aware access proxy. The Pomerium databroker service is responsible for managing all persistent Pomerium application state. Requests to the databroker service API are authorized by the presence of a JSON Web Token (JWT) signed by a key known by all Pomerium services in the same deployment. However, incomplete validation of this JWT meant that some service account access tokens would incorrectly be treated as valid for the purpose of databroker API authorization. Improper access to the databroker API could allow exfiltration of user info, spoofing of user sessions, or tampering with Pomerium routes, policies, and other settings. A Pomerium deployment is susceptible to this issue if all of the following conditions are met, you have issued a service account access token using Pomerium Zero or Pomerium Enterprise, the access token has an explicit expiration date in the future, and the core Pomerium databroker gRPC API is not otherwise secured by network access controls. This vulnerability is fixed in 0.27.1.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
github.com/pomerium/pomeriumGo
< 0.27.10.27.1

Patches

2
e018cf0fc097

grpcutil: additional JWT validation (#5304)

https://github.com/pomerium/pomeriumbackport-actions-token[bot]Sep 23, 2024via ghsa
commit
2 files changed · +96 −13
  • pkg/grpcutil/options.go+23 −13 modified
    @@ -3,10 +3,12 @@ package grpcutil
 import (
 	"context"
 	"encoding/base64"
+	"fmt"
 	"time"
 
 	"github.com/go-jose/go-jose/v3"
 	"github.com/go-jose/go-jose/v3/jwt"
+	"github.com/pomerium/pomerium/internal/log"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
@@ -92,22 +94,30 @@ func RequireSignedJWT(ctx context.Context, key []byte) error {
 			return status.Error(codes.Unauthenticated, "unauthenticated")
 		}
 
-		tok, err := jwt.ParseSigned(rawjwt)
-		if err != nil {
-			return status.Errorf(codes.Unauthenticated, "invalid JWT: %v", err)
+		if err := validateJWT(rawjwt, key); err != nil {
+			log.Ctx(ctx).Debug().Err(err).Msg("rejected gRPC request due to invalid JWT")
+			return status.Error(codes.Unauthenticated, "invalid JWT")
 		}
+	}
+	return nil
+}
 
-		var claims struct {
-			Expiry *jwt.NumericDate `json:"exp,omitempty"`
-		}
-		err = tok.Claims(key, &claims)
-		if err != nil {
-			return status.Errorf(codes.Unauthenticated, "invalid JWT: %v", err)
-		}
+func validateJWT(rawjwt string, key []byte) error {
+	tok, err := jwt.ParseSigned(rawjwt)
+	if err != nil {
+		return err
+	}
 
-		if claims.Expiry == nil || time.Now().After(claims.Expiry.Time()) {
-			return status.Errorf(codes.Unauthenticated, "expired JWT: %v", err)
-		}
+	var claims map[string]*jwt.NumericDate
+	err = tok.Claims(key, &claims)
+	if err != nil {
+		return err
+	} else if len(claims) != 1 || claims["exp"] == nil {
+		return fmt.Errorf("expected exactly one claim (exp)")
+	}
+
+	if t := claims["exp"].Time(); time.Now().After(t) {
+		return fmt.Errorf("JWT expired at %s", t.Format(time.DateTime))
 	}
 	return nil
 }
  • pkg/grpcutil/options_test.go+73 −0 modified
    @@ -9,7 +9,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/go-jose/go-jose/v3"
+	"github.com/go-jose/go-jose/v3/jwt"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/reflection"
@@ -100,3 +103,73 @@ func TestSignedJWT(t *testing.T) {
 		assert.Equal(t, codes.OK, status.Code(err))
 	})
 }
+
+func TestValidateJWT(t *testing.T) {
+	sign := func(t *testing.T, key []byte, claims any) string {
+		t.Helper()
+		signer, err := jose.NewSigner(jose.SigningKey{Algorithm: jose.HS256, Key: key},
+			(&jose.SignerOptions{}).WithType("JWT"))
+		require.NoError(t, err)
+		s, err := jwt.Signed(signer).Claims(claims).CompactSerialize()
+		require.NoError(t, err)
+		return s
+	}
+
+	key := cryptutil.NewKey()
+
+	t.Run("unexpected_format", func(t *testing.T) {
+		err := validateJWT("not a jwt", key)
+		assert.Error(t, err)
+	})
+	t.Run("unexpected_claim_type", func(t *testing.T) {
+		rawjwt := sign(t, key, jwt.Claims{
+			Subject: "subject",
+			Expiry:  jwt.NewNumericDate(time.Now().Add(time.Hour)),
+		})
+		err := validateJWT(rawjwt, key)
+		assert.Error(t, err)
+	})
+	t.Run("unexpected_claim_name", func(t *testing.T) {
+		rawjwt := sign(t, key, jwt.Claims{
+			IssuedAt: jwt.NewNumericDate(time.Now()),
+			Expiry:   jwt.NewNumericDate(time.Now().Add(time.Hour)),
+		})
+		err := validateJWT(rawjwt, key)
+		assert.ErrorContains(t, err, "expected exactly one claim (exp)")
+	})
+	t.Run("no_claims", func(t *testing.T) {
+		rawjwt := sign(t, key, jwt.Claims{})
+		err := validateJWT(rawjwt, key)
+		assert.ErrorContains(t, err, "expected exactly one claim (exp)")
+	})
+	t.Run("unexpected_expiry_type", func(t *testing.T) {
+		rawjwt := sign(t, key, map[string]any{
+			"exp": "foo",
+		})
+		err := validateJWT(rawjwt, key)
+		assert.ErrorContains(t, err, "expected number value")
+	})
+	t.Run("expired", func(t *testing.T) {
+		rawjwt := sign(t, key, jwt.Claims{
+			Expiry: jwt.NewNumericDate(time.Now().Add(-time.Minute)),
+		})
+		err := validateJWT(rawjwt, key)
+		assert.ErrorContains(t, err, "JWT expired")
+	})
+	t.Run("wrong_key", func(t *testing.T) {
+		otherKey := cryptutil.NewKey()
+		rawjwt := sign(t, otherKey, jwt.Claims{
+			Expiry: jwt.NewNumericDate(time.Now().Add(time.Hour)),
+		})
+
+		err := validateJWT(rawjwt, key)
+		assert.Error(t, err)
+	})
+	t.Run("ok", func(t *testing.T) {
+		rawjwt := sign(t, key, jwt.Claims{
+			Expiry: jwt.NewNumericDate(time.Now().Add(time.Hour)),
+		})
+		err := validateJWT(rawjwt, key)
+		assert.NoError(t, err)
+	})
+}
a2f98c87439d
https://github.com/pomerium/pomeriumvia osv

Vulnerability mechanics

Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

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