diff --git a/SOURCES/Add-recursion-limit-for-ASN.1-indefinite-lengths.patch b/SOURCES/Add-recursion-limit-for-ASN.1-indefinite-lengths.patch
new file mode 100644
index 0000000..0c4a4d0
--- /dev/null
+++ b/SOURCES/Add-recursion-limit-for-ASN.1-indefinite-lengths.patch
@@ -0,0 +1,97 @@
+From 3a5576fab22ecd21bbf72cccec5be2096e0e05c4 Mon Sep 17 00:00:00 2001
+From: Greg Hudson <ghudson@mit.edu>
+Date: Sat, 31 Oct 2020 17:07:05 -0400
+Subject: [PATCH] Add recursion limit for ASN.1 indefinite lengths
+
+The libkrb5 ASN.1 decoder supports BER indefinite lengths. It
+computes the tag length using recursion; the lack of a recursion limit
+allows an attacker to overrun the stack and cause the process to
+crash. Reported by Demi Obenour.
+
+CVE-2020-28196:
+
+In MIT krb5 releases 1.11 and later, an unauthenticated attacker can
+cause a denial of service for any client or server to which it can
+send an ASN.1-encoded Kerberos message of sufficient length.
+
+(cherry picked from commit 57415dda6cf04e73ffc3723be518eddfae599bfd)
+
+ticket: 8959
+version_fixed: 1.18.3
+
+(cherry picked from commit 207ad69c87cf1b5c047d6c0c0165e5afe29700a6)
+---
+ src/lib/krb5/asn.1/asn1_encode.c | 16 +++++++++-------
+ 1 file changed, 9 insertions(+), 7 deletions(-)
+
+diff --git a/src/lib/krb5/asn.1/asn1_encode.c b/src/lib/krb5/asn.1/asn1_encode.c
+index a160cf4fe..cd6b879f7 100644
+--- a/src/lib/krb5/asn.1/asn1_encode.c
++++ b/src/lib/krb5/asn.1/asn1_encode.c
+@@ -356,7 +356,7 @@ make_tag(asn1buf *buf, const taginfo *t, size_t len)
+ static krb5_error_code
+ get_tag(const uint8_t *asn1, size_t len, taginfo *tag_out,
+ const uint8_t **contents_out, size_t *clen_out,
+- const uint8_t **remainder_out, size_t *rlen_out)
++ const uint8_t **remainder_out, size_t *rlen_out, int recursion)
+ {
+ krb5_error_code ret;
+ uint8_t o;
+@@ -394,9 +394,11 @@ get_tag(const uint8_t *asn1, size_t len, taginfo *tag_out,
+ /* Indefinite form (should not be present in DER, but we accept it). */
+ if (tag_out->construction != CONSTRUCTED)
+ return ASN1_MISMATCH_INDEF;
++ if (recursion >= 32)
++ return ASN1_OVERFLOW;
+ p = asn1;
+ while (!(len >= 2 && p[0] == 0 && p[1] == 0)) {
+- ret = get_tag(p, len, &t, &c, &clen, &p, &len);
++ ret = get_tag(p, len, &t, &c, &clen, &p, &len, recursion + 1);
+ if (ret)
+ return ret;
+ }
+@@ -613,7 +615,7 @@ split_der(asn1buf *buf, uint8_t *const *der, size_t len, taginfo *tag_out)
+ const uint8_t *contents, *remainder;
+ size_t clen, rlen;
+
+- ret = get_tag(*der, len, tag_out, &contents, &clen, &remainder, &rlen);
++ ret = get_tag(*der, len, tag_out, &contents, &clen, &remainder, &rlen, 0);
+ if (ret)
+ return ret;
+ if (rlen != 0)
+@@ -1199,7 +1201,7 @@ decode_atype(const taginfo *t, const uint8_t *asn1, size_t len,
+ const uint8_t *rem;
+ size_t rlen;
+ if (!tag->implicit) {
+- ret = get_tag(asn1, len, &inner_tag, &asn1, &len, &rem, &rlen);
++ ret = get_tag(asn1, len, &inner_tag, &asn1, &len, &rem, &rlen, 0);
+ if (ret)
+ return ret;
+ /* Note: we don't check rlen (it should be 0). */
+@@ -1420,7 +1422,7 @@ decode_sequence(const uint8_t *asn1, size_t len, const struct seq_info *seq,
+ for (i = 0; i < seq->n_fields; i++) {
+ if (len == 0)
+ break;
+- ret = get_tag(asn1, len, &t, &contents, &clen, &asn1, &len);
++ ret = get_tag(asn1, len, &t, &contents, &clen, &asn1, &len, 0);
+ if (ret)
+ goto error;
+ /*
+@@ -1478,7 +1480,7 @@ decode_sequence_of(const uint8_t *asn1, size_t len,
+ *seq_out = NULL;
+ *count_out = 0;
+ while (len > 0) {
+- ret = get_tag(asn1, len, &t, &contents, &clen, &asn1, &len);
++ ret = get_tag(asn1, len, &t, &contents, &clen, &asn1, &len, 0);
+ if (ret)
+ goto error;
+ if (!check_atype_tag(elemtype, &t)) {
+@@ -1584,7 +1586,7 @@ k5_asn1_full_decode(const krb5_data *code, const struct atype_info *a,
+
+ *retrep = NULL;
+ ret = get_tag((uint8_t *)code->data, code->length, &t, &contents,
+- &clen, &remainder, &rlen);
++ &clen, &remainder, &rlen, 0);
+ if (ret)
+ return ret;
+ /* rlen should be 0, but we don't check it (and due to padding in
diff --git a/SPECS/krb5.spec b/SPECS/krb5.spec
index b654816..15caa13 100644
--- a/SPECS/krb5.spec
+++ b/SPECS/krb5.spec
@@ -18,7 +18,7 @@ Summary: The Kerberos network authentication system
Name: krb5
Version: 1.18.2
# for prerelease, should be e.g., 0.% {prerelease}.1% { ?dist } (without spaces)
-Release: 7%{?dist}
+Release: 8%{?dist}
# lookaside-cached sources; two downloads and a build artifact
Source0: https://web.mit.edu/kerberos/dist/krb5/1.18/krb5-%{version}%{prerelease}.tar.gz
@@ -75,6 +75,7 @@ Patch129: Ignore-bad-enctypes-in-krb5_string_to_keysalts.patch
Patch130: Fix-leak-in-KERB_AP_OPTIONS_CBT-server-support.patch
Patch131: Unify-kvno-option-documentation.patch
Patch132: Document-k-option-in-kvno-1-synopsis.patch
+Patch133: Add-recursion-limit-for-ASN.1-indefinite-lengths.patch
License: MIT
URL: http://web.mit.edu/kerberos/www/
@@ -685,6 +686,10 @@ exit 0
%{_libdir}/libkadm5srv_mit.so.*
%changelog
+* Wed Dec 16 2020 Robbie Harwood <rharwood@redhat.com> - 1.18.2-8
+- Add recursion limit for ASN.1 indefinite lengths (CVE-2020-28196)
+- Resolves: #1906492
+
* Tue Nov 24 2020 Robbie Harwood <rharwood@redhat.com> - 1.18.2-7
- Document -k option in kvno(1) synopsis
- Resolves: #1869055