diff options
| -rw-r--r-- | src/lib/krb5/krb/pac.c | 9 | ||||
| -rw-r--r-- | src/lib/krb5/krb/t_pac.c | 18 |
2 files changed, 25 insertions, 2 deletions
diff --git a/src/lib/krb5/krb/pac.c b/src/lib/krb5/krb/pac.c index 2f1df8d..f6c4373 100644 --- a/src/lib/krb5/krb/pac.c +++ b/src/lib/krb5/krb/pac.c @@ -28,6 +28,8 @@ #include "int-proto.h" #include "authdata.h" +#define MAX_BUFFERS 4096 + /* draft-brezak-win2k-krb-authz-00 */ /* @@ -317,6 +319,9 @@ krb5_pac_parse(krb5_context context, if (version != 0) return EINVAL; + if (cbuffers < 1 || cbuffers > MAX_BUFFERS) + return ERANGE; + header_len = PACTYPE_LENGTH + (cbuffers * PAC_INFO_BUFFER_LENGTH); if (len < header_len) return ERANGE; @@ -349,8 +354,8 @@ krb5_pac_parse(krb5_context context, krb5_pac_free(context, pac); return EINVAL; } - if (buffer->Offset < header_len || - buffer->Offset + buffer->cbBufferSize > len) { + if (buffer->Offset < header_len || buffer->Offset > len || + buffer->cbBufferSize > len - buffer->Offset) { krb5_pac_free(context, pac); return ERANGE; } diff --git a/src/lib/krb5/krb/t_pac.c b/src/lib/krb5/krb/t_pac.c index 0b1b1f0..173bde7 100644 --- a/src/lib/krb5/krb/t_pac.c +++ b/src/lib/krb5/krb/t_pac.c @@ -431,6 +431,16 @@ static const unsigned char s4u_pac_ent_xrealm[] = { 0x8a, 0x81, 0x9c, 0x9c, 0x00, 0x00, 0x00, 0x00 }; +static const unsigned char fuzz1[] = { + 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, + 0x06, 0xff, 0xff, 0xff, 0x00, 0x00, 0xf5 +}; + +static const unsigned char fuzz2[] = { + 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0x00, + 0x20, 0x20 +}; + static const char *s4u_principal = "w2k8u@ACME.COM"; static const char *s4u_enterprise = "w2k8u@abc@ACME.COM"; @@ -828,6 +838,14 @@ main(int argc, char **argv) krb5_free_principal(context, sep); } + /* Check problematic PACs found by fuzzing. */ + ret = krb5_pac_parse(context, fuzz1, sizeof(fuzz1), &pac); + if (!ret) + err(context, ret, "krb5_pac_parse should have failed"); + ret = krb5_pac_parse(context, fuzz2, sizeof(fuzz2), &pac); + if (!ret) + err(context, ret, "krb5_pac_parse should have failed"); + /* * Test empty free */ |